Master Research
Main Subject Teachers
Peter Adriaansz
Trevor Grahl
Master Circle Leaders
Yannis Kyriakides
Research Supervisor
Yannis Kyriakides
PIA Supervisor
Roland Spekle
Alam Hernández
Composition
3411575
20th November 2024
Koninklijke Conservatorium
Den Haag
Netherlands
Background picture by IkaAbuladze
To my mom, Claudia, my dad, Juan, and my friends Jeyana, Jurijn, Tehada, Jacob and Nanta
without whom this work would not have been possible.
To my brothers and bandmates Josh and Jaco, for their invaluable friendship and musical company.
QUICK GUIDE FOR SPACE WANDERERS:
- Navigate the space by scrolling with the mouse.
- Follow the horizon line to continue to the next chapters.
- If lost, go to the upper left extreme of the screen for teleportation.
- Hover or click on turquoise words to discover footnotes, pictures and hyperlinks.
- A pair of good-quality headphones is recommended for listening to the audio examples.
Thank you for your reading!
Contents
1. Introduction
2.2 Goals, focus and musical approach
2.3 Methodology
2.4 Audio examples
3. Headphones
3.2 Headphones and environmental sounds
3.3 Inside and Outside: personal sonic explorations with headphones
3.3.1 Travel 1
3.3.2 Travel 2
3.3 Headphones and spatial music: Bennett, Kyriakides and Youn
4.2 Tonality: Finding the key!
4.3 Rhythmic illusions: Where is one?
5. 83. Bismuth: a modest approach to spatial music
5.1 Structure
5.2 Technical set up
5.3 After thoughts
6. 10. Neon: travelling further
6.1 Concept
6.2 Online Stream
6.3.1 Linear Combinations
6.3.2 Superpositions
6.3.3 Spherical Harmonics
6.3.4 Uncertainty Principle
6.3.5 Covalent Bonds
6.3.6 Electron Transitions
6.3.7 Orbital Clouds
6.3.8 Probability Densities
6.4 Dealing with Unsynchonised Layers
6.5 Performance and Technical Set Up
6.7 Afterthoughts
7. Conclusions
8. Bibliography
1. Introduction
As Sun Ra said, "Space is the place”. Perhaps it is the only place that has existed, exists and will ever exist. But space means nothing if there are no objects in it; without reference points, space has little meaning for us.
Here on our planet Earth, we traverse, breathe and enjoy the widest space we have available: the atmosphere. This space is anyything but empty, just like the ocean, the atmosphere is a fluid; the atmosphere is a sea of gas. Through evolution, natural selection benefited those living creatures who were able to produce vibrations within fluids, those creatures which were able to produce sound. These noisy creatures rapidly dominated over the rest because they were able to transfer information and mark their territory. These creatures rapidly developed the ability to not only differentiate sound sources but to also decode their location. Some species, like bats, moles and certain salamanders, even evolved to forgo eyesight entirely, relying solely on hearing to navigate their environment.
In the YouTube video Pioneering sound art with Bernhard Leitner, Bernhard Leitner points out: “for me sound is a building material”. Sound defines places and helps us to recognise our position in space. Sound carries fundamental information for our survival and for our development as a species. Humans, not only developed one of the most complex sound systems on the planet, language, but also managed to create a system of organized sounds with no concrete meaning, which influences the way we perceive time and space through a constant pursuit of beauty and coherence of form: music.
Music is bound to space, music happens in space, there can not be music without space. However, as American composer James Dashow denotes:
"One could say that up to now, musical composition has been largely a question of “what happens when”. With spatialisation, composition now becomes “what happens when and where”."
Since the introduction of the stereo system in the 50s and 60s, musicians and listeners have become more aware of the positioning of sounds in the musical space. Soon after, the introduction of headphones into the audio market opened a whole new layer of musical perception and enjoyment, introducing an intimacy and closeness to the sound never experienced before.
Today, with the recent advent of Virtual Reality, Dolby Atmos, binaural recording and surround headphones sound artists, musicians and listeners are developing a more refined sensitivity and creativity towards sound localisation and spatialisation. Space is gradually attaining a greater significance in the way that we perceive and conceptualise music. Organisations like 4D Sound, and technologies like Wave Field Synthesis are dedicated to the exploration and development of spatial audio. Artists like Robin Minard and Janet Cardiff are pursuing innovative perspectives of space in music. Still, there are few examples of spatial music which implements the medium which delivers the most personal (and dangerously isolating) musical experience of them all: headphones.
As a gadget, headphones enables us to go into our own bubble and forget about the world, they invite us to create our own soundtrack and experience life as if we were inside a movie. As an instrument, headphones allow us to perceive sound with unparalleled purity and definition, to hear totally different sounds in each of our ears and to simulate spatiality using binaural audio.
Headphones create a new space—a personal space—and music composed for both headphones and speakers may offer alternative perspectives on how we relate to our sonic environment, specifically on how we connect to the “internal and external worlds of sound”. This music may also comment on how much we isolate ourselves from others and how our personal space relates to others' spaces.
The present work describes the creative process and the results of two electronic music pieces for speakers and headphones which were composed for exploring the perceptual thresholds in which musical materials are perceived as connected or disconnected from each other. This research presents my personal exploration into the use of speakers and headphones as a compositional medium and investigates how this medium could influence our perception of musical materials as well as my own creative process. My approach to this combination arises from a personal need to create a multilayered musical experience that explores the spaciousness of speakers and the directness of headphones, creating an interplay of relationships between musical materials.
As a theoretical framework, this work addresses different topics related to music perception such as melodic channeling, stream integration, key identification, rhythmic illusions, vibrations, spatiality of sound and the varied effects of listening to music through headphones.
This research does not extensively cover the history of spatial music and the use of headphones in spatial music composition, however, pieces and composers which are considered relevant for my work are included as well as highlights of interviews with three current composers specialised on this topic.
I hope this work ignites curiosity in the reader, sheds light on audio spatialisation, and inspires reflection on the meaning of space, connection, and isolation.
2. The way to space
2.1 Multilayered music
The reason for starting this research emerged from a persistent concern in my compositional process, a curiosity and intrigue that became clearer only recently.
As any person dedicated to creative work, my mind holds to patterns and repeatedly leans into certain concepts, ideas and images when conceiving a new composition. Recently, I discovered that my musical and conceptual imagination mostly leans towards a multi-layering of textures and a narrative independency between musical materials; I tend to wish for a type of music music in which many events happen at the same time but do not “touch” or influence each other.
During my early pieces, I sought to implement this idea through temporality, instrumentation and physical spacing between the instruments, however, none of these approaches appeared to fully work for me; there was still an unavoidable tendency for every musical event to directly affect the ones that came before and after.
"What is eventually perceived as one coherent event is therefore influenced by what happened before and what happened after each moment in time”.
––– Stephen Handel
This unavoidable concatenation of events can be illustrated with this diagram (Figure 1).
Music generally falls in the order of example A. In my vision, there are three main causes for this effect: 1) the temporal nature of music, 2) the compositional approach of music and 3) the presentation of music.
The first cause deals with the way we perceive our reality. Music happens in time and time is a line of events, one after the other. Music is a line of events, we can confirm this by looking at a score or an audio stem (Figure 2) in a digital audio workstation. Moreover, music is soundwaves, and sound-waves are perceived by our ears as a sequence of events, one after the other. Unlike vision, which allows us to perceive an object as a whole and skim through different points of a picture, hearing allows us to perceive one point at a time. In this sense, vision is two dimensional, while hearing is one dimensional. Hence, music could be considered to be one dimensional.
The second cause is the narrative approach to composition which reinforces the linear perception of music. The music we are mostly attracted to is the music which tells us a story, with or without lyrics; we tend to prefer music with a narrative, that which has an intro, development, climax and ending. Symphonies, operas and songs fall into this category. Furthermore, our brains are also responsible for merging auditory information together into patterns or objects and hence, producing a sensation of connection between them. It has been demonstrated that, for evolutionary reasons, our brains are naturally wired to recognise familiar patterns or objects even where there are none.
The third and final cause is the way music is presented. In a regular music event, music comes from a single music source and happens in one single music space. In this situation the whole attention of the listener is focused on this single source and on this single space, generating a kind of tunnel of musical events. This reinforces mono-dimensionality in music as a tunnel is ultimately a line. Moreover, the sounds, as far apart as they could be, ultimately merge and blend into each other, filling up the space and becoming one single input.
“The trouble with space is that it’s the whole piece. It’s the sounds and everything. The impressions of space are created through the types of sounds and their temporal experience. Space is the whole thing. It is not usually something that people perceive as separate from the sounds themselves, although the composer might consider space separately. For the listener, they’re all moulded into one. That’s why we end up talking about the piece as a whole, because the whole is the space or spaces of the piece”
––– Dennis Smalley
Sharing the same concern as Smalley, I devise the possibility of spatial music in which a true layering is possible, in which sounds do not end up being one whole thing and in which we are able to navigate these dimensions at will and perceive different relationships and interactions of musical layers.
Understanding the fact that we are bounded to time and to our senses and that we irremediably can only perceive only musical events in a linear way –one at a time–, can we pursue to expand our perception of the relationships between musical events by devising a multilayered musical experience? Can we construct this multilayered musical space through the combination of headphones and speakers?
2.2 Goals, focus and musical approach
The main goal of this research is to draw attention into the use of headphones as an additional implement for composing spatial music and to investigate how this medium could influence our perception on the relationships and hierarchies of musical materials. Additionally, it also works as a personal exploration on how the usage of spatial audio may influence my own composition.
The focus of this research is not on musical abstraction but rather on what we could call “conventional music”, that is, music which follows the traditions, conventions, theories, practices and aesthetic preferences of western music composed with the 12-tone equal tempered scale and based on the notions of rhythmical hierarchies and tonality. For abbreviating, this type for music will be refered to as "pitch-and-rhythm based music". Aside from a personal preference, the reason behind this choice is that this sort of music, deeply integrated in our memories by cultural influence, ignite in our minds potent and unparalleled correlations of forms, shapes and contours; relationships which I believe to lay a considerable potential for further exploration in their perception. Finally, to clarify, music with alternative tuning systems is not covered, discussed or explored in this research.
Regarding spatiality, I am also not interested in spatialisation of audio for the sole sake of surround sound, audio immersion, “3D/4D experiences”, special effects or any technique that could degrade sounds down to artifice.
I am interested in investigating if the combination of headphones and speakers can influence the way our minds relate to musical events and sounds as related or as unrelated and how the attention shifts between these two aspects. When does a musical event or musical layer become foreground or background? How can the narrativity, linearity and development of musical composition be affected by this media?
Regarding musical style, this work is based and inspired on Synth-wave, Electronic Dance Music (EDM), House and Trance music. I decided to use synthesisers for their purity of sound, infinite malleability and for being the instruments in which I find my most authentic expression.
2.3 Methodology
The methodology of this research consists of bibliography, interviews, creation and experimentation.
After some time of compiling articles and books, I have dived into the concepts of spatial audio and spatial music with self-experimentation in the studio; trying out music and sounds and selecting the materials which I found substantial for further exploration and development. This progressed into the composition of my first two pieces of spatial audio: 83. Bismuth and 10. Neon.
Additionally, in order to attain a more informed vision on the current state and context of spatial music, I conducted interviews with three composers with experience on the topic: Justin Bennett, Yannis Kyriakides and Ji Youn Kang.
2.4 Audio examples
Along with the exposition in the Research Catalogue, audio examples are included. Headphones are recommended for listening since most of them are processed in binaural audio using DearVR Music. For practicality, audio clips from 83. Bismuth and 10. Neon have been binauraly adapted for listening with headphones. Please note, these versions are illustrative and by no means a faithful representation of the spatial aspect of the pieces.
3. Headphones
There is a wide wide variety of portable music reproducing devices that can be worn in the ears or around the head such as earphones, closed-back, open-back, noise-cancelling, EarPods and in-ears. For practicality, all these types in this chapter will be referred to as headphones.
3.1 Headphones vs. Speakers
Ever since their introduction in the market in 1979, headphones rapidly became the most popular device for listening to music due their portability and affordability. The advent of this new medium brought substantial changes to the way music is experienced. One remarkable change was that audio engineers and producers began taking into account that music was now going to be split dichotically, namely, into two entirely isolated inputs: the right and left ears. In this way, hard panning and dual mono mixes began to decline and music production started to focus on creating the illusion of a space through the headphones.
Evidently, the introduction of headphones brought an entirely new social role for music in society as music listeners now were able to isolate themselves from the world and get immersed into their own “bubble”; music started to become a tool for avoiding social interaction. In 1999, twenty years after the release of the Walkman in 1979, Phil Patton stated the following in his article “Humming Off key for two decades”:
"On the original model Sony Walkman, introduced twenty years ago this month under the trademark "Soundabout," was an orange button [ ... ] it also had a second earphone jack and when you pushed the orange button, the sound emerged into two sets of phones and two listeners could talk to each other through a microphone. It was a revealing feature: even Sony was apparently worried about the solitary qualities of the Walkman. The orange button was like a panic button, an emergency "share" feature. The company was that hesitant, Sony cofounder Akio Morita wrote later, to release a product that was somehow so selfish. [ ... ]"
––– Phil Patton
On the other hand, the seclusion that headphones provided––an unprecedented intimacy for the music experience––fostered deepest relationships between artists and listeners, as the music was now an appendage of the body. Furthermore, this isolation also brought benefits to users who experience anxiety in crowded spaces, providing them with a sensation of safety.
3.3 Inside and Outside: personal sonic explorations with headphones
I have listened to music in headphones and earphones ever since I can remember, I recall listening to music with my dad’s cassette player when I was three years old. Ever since, I have always enjoyed the sensation of going into another world by shutting off the external noise and diving into the sonic universe of the headphones, I find it to be uniquely calming and healing.
However, there have been occasions when this immersion has been incomplete, interrupted, or disturbed. I recall that in high-school I was allowed to listen to music in the classroom but using only one earphone. Whenever I travel in the subway, I often must pause the music to pay attention to which station is next. And sometimes, the external noises get so loud that the sound coming from the headphones no longer creates a sense of immersion, outside and inside get merged.
These situations are analogous to the multilayering of sounds which I refer to in chapter 2. For headphone and earphone users, this multiplicity of sounds is very much present in our lives and it happens more often when we listen to music in an outdoor situation; these situations are mostly travels such as listening to music with headphones in the street, bus or the train. During these trips our attention constantly shifts from the music source (headphones) to the external ambient sounds, this generates a multi-layered narrative constructed both by the music and the ambient sounds. Depending on the situation, one of these two elements becomes the foreground while the other becomes the background.
The shift in our attention between these two layers may be mainly caused by two parameters of the sound: loudness and proximity. In general, regarding loudness, louder sounds are more prominent to us than softer sounds. However, the effect with proximity is not as intuitive. If a sound is more proximate to our ears it does necessarily mean it will stand out in our perception. Closer sounds may be louder and intimate but they are small in magnitude, farther sounds may be softer but their greater spatiality grant them with more volume and a greater potential of becoming the centre of our perception. External sounds enfold our bodies, generating a sort of sonic environment where the other, smaller and closer sounds from the headphones dwell.
My fascination for this multilayering led me to try some experiments with my headphones during a couple of travels in the train from Amsterdam to The Hague.
3.3.1 Travel 1
During my first trip to Amsterdam, I played some music on my phone and listened to it with a pair of earphones. I tried to merge and experience both the music and the ambient sound layers by constantly adjusting the volume of the music on my phone. The music I selected for his experiment was an ambient record by Kensuke Mitome & Gota Wakabayashi, a minimalistic music which I considered to be suitable for being not too loud and not too complex to draw my attention entirely from the sounds coming outside of the earphones.
Green Labyrinth - Kensuke Mitome & Gota Wakabayashi (1993)
A study realised in 2011 by Ana Tajadura-Jiménez et al. demonstrated that people who listen to positive emotion-inducing musical excerpts using headphones are more able to tolerate proximity to unknown individuals. In other words, their personal space is reduced.The opposite conditions showed corresponding results, people who listen to negative emotion-inducing musical excerpts through speakers become less tolerant to be near strangers; their personal space gets expanded. The researchers explain that positive emotion-inducing musical excerpts played close to a person’s body create a sensation of safety and self-reassurance. In contrast, negative emotion-inducing musical excerpts coming from a distant source, such as speakers, is perceived as a threat, making anything or anyone outside the listener’s body feel less safe. In short, listening to emotionally positive music helps the listener to better endure crowded environments such as public transport and airports.
Besides creating a personal space and a sense of isolation, the use of headphones also affects the way music itself is perceived. The proximity of the sound coming from the headphones, aside from providing an unparalleled transparency and detail, causes the sounds to be mapped differently in the mind of the listener. Several neurological studies have demonstrated that sensory information is processed differently depending on its distance from the receiving body; as an evolutionary consequence and for ensuring survival, the brain developed specialised areas which are focused on processing and receiving either far or near stimulus, a trait which aids a subject to recognise its own personal space and rapidly notice the presence and distance of potential dangers such as natural disasters or predators.
In contrast to headphones, speakers offer a shared musical experience and foster social interaction, whether that is desired or not. Additionally, since speakers are normally listened to from a distance, they create a natural acoustic atmosphere. “Thus, the spatial representation of sound is different if one listens to the same musical recording on speakers or headphones”. Furthermore, the vibrations produced by the speakers also influence the emotional responses to the music. Several studies have proven that sounds which also produce vibrations on the body of the listener have an increased emotional and perceptual response than those which don’t. It has been demonstrated that the vibrations produced by low frequency sounds have a strong impact on the human vestibular system, the system responsible for body movements.
In the discipline of audio engineering, it is common knowledge that the mixing process is significantly affected by either utilising speakers or headphones, one of the reason to this is the way low frequencies are perceived. In short, thanks to the vibrations produced in the body, low frequencies are better perceived when listened through speakers.
The effect of vibrations in the musical experience is so relevant that several experimental devices have been designed to improve the perception of our everyday music listening. One of these is the LIVEJACKET, a wearable jacket with 22 speakers designed in 2018 by Satoshi Hashizume, Shinji Sakamoto, Kenta Suzuki, and Yoichi Ochiai at the University of Tsukuba, Japan. In their investigation, they concluded that the LIVEJACKET considerably enhanced the musical experience of the users, who felt as if they were singing the music and expressed a wish for attending a live concert.
Contrastingly, another study, held by Agata Zelechowska et al. in 2020, focused on studying the bodily reactions of subjects when listening to Electronic Dance Music (EDM) through headphones or speakers. In their results, subjects who listened to music through headphones moved more than those who listened through speakers. The authors offer a number of explanations to this. First, the covering of the ears filters environmental sounds, providing a more immersive musical experience. Secondly, it is likely that the intimate setting of the headphones aided the subjects to ignore the laboratory setting and provided them with more confidence to respond to the music. Thirdly, the proximity of the music through the headphones evidently stimulated the vestibular system. Whether this stimulation is stronger than that caused by the speakers is not clarified by the authors, who asseverate that more research is needed to clarify this question. Still, the final results of the experiment show that people tend to move more when listening to music with headphones than with speakers.
3.2 Headphones and environmental sounds
Different types of headphones offer different levels of sound isolation for the user. Some of them, known as noise-canceling phones, are specially designed for this purpose and can have an average environmental noise reduction from 20 to 40 dB. However, this isolation has its limits and environmental sounds from the “outside” of the phones will always leak, either through our ears or through vibrations in our body.
A study run by Kazuhiro Hara et al. in 2010, demonstrated that environmental noises affect the preferred listening level of users listening to pop and rock music (music genres with a considerably loud average volume) even when wearing intra-concha earphones.
Being so, headphone users always experience a mixture of sounds coming from the headphones and outside the headphones. This mixture of sounds is a field of study on its own and has inspired sound artists and engineers to create devices which mix and transform these two sound worlds in order to create something new. This idea is closely related to the concept of augmented reality: an interactive experience which combines stimuli from the real world with computer generated content.
A notable example of an augmented reality audio device is Ambient Addition by Noah Vawter. In his words:
“[Ambient Addition] It is a portable Walkman that immerses the listener in an artificial sonic world incorporating the ambient sound around him or her. Consisting of a pair of headphones with small, embedded microphones, and a pocket-sized digital signal processing (DSP) system, it continuously records, analyses, transforms and plays back environmental noise into more musical form. Through its outward appearance and sonic-bridging capabilities, it reduces isolation. The remainder of this thesis presents compositional techniques and details on design decisions, development, algorithms and results.”
––– Noah Vawter
In this way, Noah’s device offers the possibility of mixing both sound inputs for creating something new, additionally, it kindles awareness in the listeners about the dynamic relationship with their surroundings.
When I started this listening exercise, I focused my attention on the intrinsic characteristics of the sounds and attempted to ignore the natural tendency of deducing the causes and sources of these sounds, Dennis Smalley describes this tendency as source bonding. This mode of listening I was approaching is defined as entendre by Pierre Schaeffer in his collection Traité; this is also known as morphological listening since the the listener’s focus are the frequencies and amplitudes of the sound rather than its source or spatiality.
During this first experiment I found out that, being one layer compounded by disorganised sounds (noises) and the other one with organised sounds (music), it was quite difficult for me to conceive this experience as a unified soundscape, some sounds were irremediable perceived as unrelated, intrusive and/or accidental. Still, some moments during this trial were somewhat effective and at certain moments I was able to perceive a duality of narratives happening at once.
One remarkable mix was when I played a track in the threshold of audible volume, with the music being barely on top of noises from outside the earphones. This immediately threw the music into the background and provided it with a dreamy and ghostly character; it almost felt as if I was imagining it, just as when we say we have a song “inside our head”.
This first experiment let me realise that the music I was reproducing had melodic and rhythmical characters that were too dominating for it to be successfully merged with the external sounds, in other words, I was absorbed by it and there was no space for other sounds to fit or make sense. Music with rhythm and melody may be more prone to be perceived as a whole entity in our brains, for it is complete in its narrative and it easily draws our full attention, leading us to filter out any other sounds.
3.3.2 Travel 2
For my second travel, the music I selected were the Quatttro Illustrazioni for piano solo by the Italian composer Giacintto Scelsi. Additionally, this time I substituted the earphones with semi-open headphones.
The results of this second experiment were rather richer than the first one. Again, when starting the listening, I focused my attention on the frequential content of every sound, disregarding its sources and not discriminating against any of them. This time, provided the music was more abstract in quality, the sonic environment of the train appeared to melt into the sonorities of the piano. The music of Quatttro Illustrazioni is atonal, minimalistic and does not have a steady beat or consistent rhythm, these characteristics allowed this music to merge more effectively with the aleatoric nature of the sounds in the train.
Illustrazioni - No. 4, Krishna - Avatàra – Giacinto Scelsi
I was lucky enough to be in a particularly noisy wagon: composed of intermittent conversations, plastic bag noises, ventilators and ringtones. At certain moments during the listening, there were sounds which I was not able to tell whether they came from outside or inside the headphones. Whenever this happened, I was tempted to move my head or remove the headphones to find out the cause, however, I resisted the need and enjoyed the mystery of these sounds.
I attribute the effectiveness of the merging of Scelsi’s music with the environment to the following causes. First, as I mentioned, because the music is atonal and contains a larger number of pitches and contours than conventional harmonic music, it increases the probability for sonorous connections to be perceived. Secondly, the characteristic resonances of the piano, especially in the lower register, generate a rich collection of overtones which can easily merge with environmental noises. Thirdly, the sound of the piano in this particular recording has a lot of room ambience (reverberation), this blurs pitches and generates complex sonorities which are prone to blend with ambient sounds.
In the same lines as Noah Vawter, this second travel opened to me the possibility of employing the spectral qualities of the sounds of certain environments (train, beach, street, forest) to compose music for headphones that is to be heard while traveling in these environments. While a great amount of environmental-based music has been composed, this concept differs in that field recordings would not be employed to construct it, and that it would not be abstraction-based but rather pitch, harmony and melody-based. This would create a fascinating soundscape of controlled (music coming from the headphones) and uncontrolled (environmental noises) sounds which interchangeable merge and separate from each other. This idea is yet to be probed and developed.
3.3 Headphones and spatial music: Bennett, Kyriakides and Youn
This section is mainly focused on the utilisation and inclusion of headphones in spatial music, for further reference and a comprehensive history of spatial music I recommend reading the doctoral thesis of Enda Bates, The Composition and Performance of Spatial Music.
Spatial music has a vast historical background, having its first recorded appearances in the sixteenth century within the Early Christian tradition. Spatial music has had numerous motivations and perspectives throughout the centuries; early composers such as Adrian Willaert used space for enhancing the narrative of the work, while contemporary composers like Henry Brant employ space to preserve clarity when contrasting musical materials are combined.
As wide as the spatial-music practice is, there are few examples of composers which have explored the combination of headphones and speakers in their artistic work. The reason for this may be both artistic and practical.
By being so close to the ear canal, sounds coming from the headphones cause no reflections in space, therefore eliminating acoustic cues and aural orientation in the listener. Furthermore, headphones, strictly speaking, do not offer stereophonic image since the interactions, reflections and micro-differences caused by two speakers in a room are not present. However, headphones offer alternative possibilities of hearing such as dichotic listening and sonic counterpoints caused by sounds coming from outside and inside the headphones.
For having a wider understanding on the subject, I held interviews with three contemporary composers which have explored the utilisation of headphones in their artistic work.
Yannis Kyriakides is a Cypriot Dutch composer based in The Hague, Netherlands. His work mainly focuses on memory, language, and perception, combining acoustic and electronic instruments and exploring the expressive layers of the voice.
In his piece Wordless, Yannis combined headphones and speakers out of necessity. This piece, commissioned for the ARGOS festival 2004, was planned to be performed in the middle of the Central Station in Brussels, however, the reverberations in the hall made it difficult to perform any sort of electronic music. The promoter of the concert, suggested to have the piece performed through Silent Disco, Yannis took it further and proposed to use both headphones and speakers. This piece is built with non-verbal vocalisations taken from various interviews about music. Yannis took advantage of the headphones to provide the listeners with a more intimate experience since all the breaths, whispers and mumblings from the voice recordings were right next to the ears of the audience.
Yannis considers headphones as a valuable resource for creating virtual spaces as they are useful for creating a sense of immersion. In the same lines, sound artist Ji Youn Kang, considers that sounds become "the whole Universe” when heard through headphones, however, she does not consider that headphones can achieve true intimacy as the sounds happen all around the ears and not from a single point in actual space.
Ji Youn Kang is a is a South Korean composer, performer, and sound artist based in The Hague, Netherlands. Kang’s mainly works with spatial audio exploring the relationship between musical and spatial gestures. Her works are primarily composed for spatial audio systems such as the Acousmonium and the Wave Field Synthesis (WFS).
According to Ji, headphones offer an interesting field for exploring their combination with speakers since they offer a fully different hearing experience. Still, she points out that spatial exploration through headphones should not derive into mimicking (or trying to mimic) a speaker hearing experience, as the headphones, in the end, are just two speakers, and there can be just so many information that can be transmitted through them before sound becomes compressed and masking effects begin to occur.
Another notable artist in the spatial music field is Justin Bennett. Justin Bennett is a sound and visual artist based in The Hague, Netherlands. Besides music he also studied sculpture and integrates this discipline into his sound installations. One of Bennett’s most known works is his Sound Walks, audio pieces where the listener follows a determinate route and experiences a kind of augmented reality through the combination of prerecorded sounds in the headphones and environmental sounds.
Justin considers that headphones have the power to transport the listener into "another world" and are still a promising tool for further exploration in sound art. Justin employs headphones mainly for environmental sound design with the goal of offering the listener with a private and intimate experience. He emphasises that speakers and headphones cannot be compared and that both sources have their strengths and weaknesses. Speakers are better when working for long periods of time, since dynamics are clearer, while headphones allow for a more detailed hearing for analysing works by other artists.
In short, with the introduction of headphones, new ways of experiencing music emerged, significantly influencing how it is enjoyed and perceived in society. Psychologically, listening through headphones has shown to affect the body and emotions differently than using speakers. Today, this contrast continues to be enhanced and keeps inspiring artists to explore headphones as a unique medium for expanding their musical expression.
When listened through speakers the stream Integration effect is stronger due to the reflections of the room. This is exemplified with the following binaural simulation.
Even when one of the signals has spatial movement in a dichotic way (with hard panning) and with a simulated different reverberant space, the stream integration remains dominant and pattern b) is heard. A more percussive timbre has been selected for the following example.
When the timbre of one of the signals is changed, the disjunct melodic patterns become more evident. This is of course a continuum, and the less similar both signals are the less stream integration will occur. The following example shows: 1) same timbre in both channels, 2) slight timbral difference in right channel and 3) accentuated timbral and spatial difference in right channel.
In the third part of the example, the difference between both sources is such that the internal properties of the disjunct pattern come to the foreground, however, aided by the recent memory of the intrinsic melodic relationship between the two, both signals are perceived as melodically corresponding.
Memory and tonal perception are of great significance for the ability to recognise a melodic contour, especially when this melody is surrounded by other musical elements. In 2007, Stephanie Vuvan and Mark A. Schmuckler ran a study in which they asked subjects to recognise melodic contours when they are interleaved with other melodies. The task was to identify if the interleaved melody matched the contour of the target melody. The interleaved melodies varied in degree of interval distance, temporality and tonal relationship.
The results showed a counterintuitive surprise. The contour of melodies interleaved with non-related tonal melodies were harder to recognise than those interleaved with closely tonal-related melodies.
The following example shows 1) the target melody, 2) target melody interleaved with a melody of related tonality and 3) target melody with interleaved with a melody of not related tonality.
All melodies match in contour, but the tonal differences in 3) hinder the recognition of the contours.
The separation of both melodies in space substantially helps to recognise both contours, as both melodies are heard and conceptualised as independent entities. When movement is added, rich interplays of connection and disconnection appear. The following example illustrates 1) separated melodies in space and 2) added movement.
Is important to remember, that all the examples contained in this section are not real musical situations where factors such as expressiveness, dynamics, phrasing, articulation and accompaniment would greatly influence and determine the amount of connection between themes and melodies.
To conclude, spatial movement may play a determinant role in the perception of melodic contours. The effects of stream integration and stream segregation can be powerful compositional tools for creating counterpoints of relationships between melodies in a spatial composition. Headphones would be of great importance when enhancing stream segregation, as the signals would not be mixed up with the reflections in the room.
Spatial movement can help to accentuate the rhythmic or melodic aspects of the pattern. In the following example, every beat is located differently with the first beat accentuated with digital reverb and by being positioned in the centre. This sort of hocket, becomes more aggressive in the headphones since the sounds are not mixed by their reflections in a room.
Is worth mentioning that rhythmic illusions need a counterpart to work best. This counterpart may be any musical material which remains steady during the rhythmic detour. In this way, the listener can perceive the tension between both materials and a rich rhythmic counterpoint is generated. As british drummer Bill Bruford points out:
"If you merely present the odd number [pattern] against nothing, there is no tension and therefore [no] excitement; excitement in music comes from tension and release. If you merely offer the the complex beat, people tend to only perceive it as a complex beat. If you offer the simple at the same time: there is the tension, there is the excitement, there is music!"
––– Bill Bruford
To conclude, rhythmic patterns with a steady pulse continue to be a promising field of exploration in spatial music. The audio processing tools being developed today offer alternative perspectives for conceptualising and developing musical materials, which kindle creativity and foster innovative ways for understanding and perceiving rhythm.
4.4 Melody: Drawing the line
It has been proposed that the recognition of a melodic contour is an inborn quality of humans as it is developed inside the womb through maternal singing. Furthermore, the melody is by far the most prominent musical form to which we are exposed, since it is present in most of musical genres and virtually in every musical tradition.
Being so, humans have a natural ability for conceptualising closely related sounds as melodies. A study run by David Butler in 1979 demonstrated that sounds which have a correlation in pitch are perceived as a continuous melody, even when their localisation in space is different.
During this study, music students were asked to hear a musical pattern with headphones and describe the melodic contour of what they heard. The material they listened to, shown in Figure 6, were two simultaneous C Major scales, one ascending and one descending, spread dichotically between the left and right headphones (a). Both scales were produced with sine waves in the same octave with no frequential differences. The results showed that 93.8% of the subjects perceived the material as two tetra-chordal arches (b), 6.2% perceived the two contrary scales (c) and none of the subjects perceived the disjunct melodic patterns. This effect of recognising a particular melodic contour is known as Stream Integration, its contrary being Stream Segregation.
4. Music perception in space
When composing pitch-and-rhythm-based spatial music, it is essential to consider the differences in perception and compositional approach when compared to spectrally oriented spatial music.
Music which is not based in pitch and rhythm is often focused in offering the listener alternative virtual spaces where the spectromorphological qualities of sound are the main subject, that is, their duration, location, envelope and frequential content. This scope is benefited when the sounds do not present stable structures such as steady pulsations or a hierarchy of pitch, that is to say, when it is composed mainly with noise. The absence of regularity invites the listener to focus their attention on aspects of the sound which otherwise would be ignored or taken for granted.
On the other hand, pitch-and-rhythm-based music ignites a different sort of listening, where the focus is, of course, the hierarchical relationships of pitches and pulsations. The main difference lies in the natural tendency that humans have for recognising auditory patterns, an ability developed throughout evolution to ensure survival of the individual. To this day, the Gestalt principles of proximity, regularity, good continuation and common fate remain as a universal explanatory basis for the perception of rhythmic and melodic structures in music.
When melodic and rhythmic structures are present in a composition the spectromorphological aspects of the sound are inevitably obscured by the dominance of these auditory patterns. However, by combining spatialisation techniques of acousmatic music with principles of music perception we may be able to compose pitch-and-rhythm based music in which space acts as a predominant factor for defining musical structure.
4.2 Tonality: Finding the key!
The perception of tonality is of substantial importance for my work since the stylistic approach I pursue consists in isolating, combining and overlapping multiple musical motifs. These motifs require to be clear in their tonality regardless of their musical surroundings or musical context, in this way, they can be apt for being combined with other materials without losing their tonal identity.
Key recognition is one of the most studied fields of music perception in the areas of musicology, psychology and neuroscience. Among the numerous studies conducted, two models for explaining key recognition are the most prevalent: structural-functional information and event-distribution strategy.
The structural-functional information model is focused on intervalic structure. Within this model model, David Butler and Helen Brown proposed the “intervalic rivalry theory”, which establishes that key is recognised when the dissonant intervals of the scale are present (namely minor seconds and tritone) along with a non-ambiguous tone. Similarly, Iwao Yoshino and Jun-ichi Abe , propose that key recognition arises when trying to interpret the pitches of a melody as part of a certain collection of tones like a diatonic scale or a chord.
Alternatively, the event-distribution strategy is focused on the presence and distribution of pitches. With this model, Carol L. Krumhansl and Mark A. Schmuckler propose that key finding can be achieved when matching the duration of pitches in a piece of tonal music with the hierarchies of pitches within the 12 major and minor tonalities. In the experimentation with subjects, this model works by playing either a scale or piece of music followed by an isolated pitch, the listeners are then asked how much this subsequent pitch matches the music previously heard.
These two models have been treated independently and have been even considered to be contradictory. However, subsequent studies run by Schmuckler in pair with Robert Tomovski have demonstrated that both models for explaining key finding may be complimentary. In their studies, they found out that intervals influence the recognition of pitch distribution since melodic contours which intervals match those found in diatonic musical materials also present pitch distribution similar to that found in tonal music. In conclusion, a musical material which both intervals and pitch distribution match the hierarchies of a certain tonality, will enhance key recognition.
Based on the research by Schmuckler and Tomovski, four musical examples have been created to demonstrate these principles. This can be observed in Figure 3.
A good and clear example of tonicization in pop is the chord loop of Call My Name (COE Remix) by BLAEKER:
||: F#m - EM - BM ——-
C#m - BM - AM ——- :||
Built upon the scale of E Major, this sequence tonicizes B Major since the F#, E, B bass sequence intervalic contour describes a Vm, IV, I progression, a chord sequence broadly used in pop and jazz practice. Besides, the B Major chord lasts 4 beats, which adds predominance. A Major is not tonisized since the chords which precede it move in descending direction and by adjacent tones, softening the arrival to A. Moreover, the A Major, lasting 4 beats and being localised at the weakest rhythmical point of the loop (last bar), provides a greater a sensation of inertia and expectation for restarting the loop and reaching F# minor.
The predominance of chords in this progression can be influenced by spatial treatment. The following example follows the practice of diffusionism in which a previously composed musical material is spread around space. In this example, chords have been given a motion in space which do not match the harmonic rhythm of the sequence, unexpectedly reinforcing certain harmonies and hindering others.
4.1 Spatiality of sounds
The spatiality of a sound is directly intertwined with its internal properties, this is what Frank Ekeberg Henriksen calls Intrinsic Space. As he points out, "one cannot manipulate a sound without concurrently altering its spatial properties”.
The following terms could be employed for defining the spatiality of a sound:
Magnitude: How big the sound is perceived. This is influenced by characteristics such as duration, sound pressure, frequency content and how much the sound is spread in space.
Localisation: How easy it is to locate a sound in space
Density: How "impenetrable" a sound appears to be. Sounds with high sound pressure level and high harmonic content feel heavily packed, making it difficult to “hear into the sound”.
Perceived distance: How far away the sound appears to be. This is dependant on multiple parameters of sound and is not always correspondent with the actual distance of the sound.
In Table 1 possible relationships between the parameters and spatiality of a sound are proposed.
As the descriptions in Table 1 show, these parameters are not independent and are interconnected to each other. This is true for natural acoustic sounds. In electronic music, however, one might be able to create sounds with an unnatural spatiality. Eg. A high filtered contrabass. It is low in pitch but since lower frequencies have been removed it is smaller in magnitude and easier to locate.
Besides, this table only describes sounds which do not change over time or move around space. Movement affects the energy in the sounds and opens possibilities for modifying their level of localisation. Eg. A violin, with a highly directional sound, can be spread out in multiple speakers to blur its location.
Regarding movement, sound can have the following motions: left and right, up and down, far and close, focused and dispersed. However, is important to point out that not all trajectories are audible due to the psychoacoustic effects of certain frequencies and of the limitations of human hearing. Sounds moving in the sides have a less defined trajectory than sounds moving in front of the head, and back and forth motion is barely audible as a mild spectral change.
Motion of sound is determined by direction and speed. Contrary spatial motions can provide a rich spatial counterpoint in a composition and can increase definition and independence to sounds; while different speed and changes in speed are potent tools for managing energy levels in the music.
With these notions of spatiality in mind, it is possible to propose techniques for manipulating structural functions of pitch-and-rhythm based music. At a micro-level, it could be possible to manipulate the aspects of:
Prominence: How much musical materials stand out from the others.
Connection: How much two or more musical materials are perceived as related or non-related.
At a macro-level, spatialisation can work as a tool for enhancing structural functions in music. Frank Ekeberg Henriksen describes the following components of musical structure:
Increasing intensity: growth in texture, volume, energy, harmonic tension etc.
Decreasing intensity: decrease in texture, volume, energy, harmonic tension etc.
Stasis: unchanging levels of energy with a sensation of rest and stability. Low energy is not implied.
Latency: unchanging levels of energy with a sensation tension and expectation. Low energy is not implied.
In Table 2, possible relationships between spatiality and the prominence and connection of musical materials are proposed. Based on this, it would possible to manipulate the macro aspects of musical structure through spatialisation.
These four bits, written in the key of A major, show:
a) corresponding hierarchical distribution of key pitches and inclusion of dissonant intervals,
b) corresponding hierarchical distribution without dissonant intervals,
c) non-corresponding hierarchical distribution and non dissonant intervals,
d) additional example with one pitch modified, suggesting a different key.
As expected, a) and b) offer great and good clarity for key recognition while examples c) and d) are the ones which offer the less clarity.
When treating these examples with spatiality is possible to either reinforce or counteract the level of relationship between the pitches. Starting with example a), a simple way to induce a major level of integration would be to locate all the sounds in the same place. In this example, this works by changing the stereo signal to a mono signal. Additionally, a mild movement from left to right can be added to reinforce the perception of a single “piece of sound”.
For reinforcing the ambiguity of pitch in example b), pitches of less hierarchical degree can be reinforced the by granting them with more magnitude. In this example this can be achieved by adding reverb and reinforcing the apparent width of the sound. Accordingly, the other pitches can be reduced in magnitude by making them mono. In a situation with a real room, it would be effective to locate the ambiguous tones in the speakers, as these would grant them with more magnitude and hence, more prominence.
A counteracting technique can be tried for example c), where reinforcing the tonality of A Major can be tried. In this case, the melody and pedal note are granted with more magnitude by adding reverb. The rest of the pitches are segregated in space for debilitating the principle of good continuation. Additionally, the attack is slowed down in these pitches for simulating distance. In a situation with speakers, the melody would be spread in all sound sources, which would provide it with natural reverb.
Finally, the overall pitch relationships of example d) can be debilitated by segregating the pitches between left and right sides. In a speaker-headphone situation, this segregation would work even better thanks to the differences in sound quality and distance.
It should be taken into account that these examples are isolated bits, have no context and do not conform a full musical situation. In reality, key recognition is influenced by several additional musical parameters such as dynamics, instrumentation, melodic contour and even cultural context or stylistic knowledge. Besides, other western music genres which do not align with the interval and melodic treatment of western music tradition, such as rock, pop and electronic music, are also subject for key recognition.
In his investigation Diatonic and Chromatic Tonicization in Rock Music, Brett Clement explains the principle of tonicization in rock and pop music, where context plays a defining factor for understanding a chord as tonic.
Note the micro changes in perception of tempo. Closer bits appear to be faster than farther away bits.
To sum up, the influence of spatial treatment in the perception of tonality lies in modifying the prominence of certain pitches based on their localisation and magnitude in space.
4.3 Rhythmic illusions: Where is one?
As with tonality, the perception of meter in music is a continuum and it varies depending on multiple factors. Further, contrary to what we may believe, the understanding of rhythm is not embedded only in the temporality of the pulses, but also in their melodic contour.
Rhythmic illusions are relevant in this work because they allow us to generate materials with varying degrees of correlation and connection. When spread around space, musical materials with different rhythmic relationships create rich rhythmic soundscapes where things appear to intercalate between coinciding and not coinciding. Furthermore, in large distances of space, rhythm becomes more interesting as micro-delays caused by the speed of sound begin to be apparent.
A rhythmic illusion is a term coined by the British drummer Gavin Harrison. In his book “Rhythmic Illusions”, Harrison presents a couple of techniques in which the listener can be “fooled” by the patterns played on the drums.
The first of these techniques is temporal displacement, in which a certain drum pattern is moved forwards or backwards by a certain division of the pulse to give the illusion that the meter has changed. This is just a matter of a different placement of the notes in the staff.
A notable example of this principle is Vinnie Colaiuta’s drum part in I'm Tweeked / Attack of The 20lb Pizza, the first track of his solo album of 1994. This part, transcribed in Figure 4, consists only of shifting the position of the drum pattern along the 2nd, 3rd and 4th partials of the 16th's subdivision. As simple as it is, the music is almost impossible to follow along without the use of a click track.
When treated in space, moving the rhythmic section to different locations accentuates the rhythmic asynchrony, however, following the beat becomes easier, since the steady instrument (electric piano) is the closest to our ears.
The contrary effect, more like to the original track, is to have the drums as the most prominent sound and move the steady instrument in space. In this way, the drums become the root, and the electric piano appears to "be out of groove”.
The second rhythmic illusion Harrison proposes is Modulation. Just as one modulates harmonically from one key to another, one can modulate from one time signature to another. This concept gets more interesting when this modulation is a mere illusion, where the whole song retains its time signature and the drum pattern changes, accompanied or not by other instruments. This new pattern, however, needs to be clear enough to provide a solid rhythmic foundation and make this illusion work best.
The following example is from an exercise I did some years ago, where the drum modulates from 5/4 to 5/16th's groupings.
When treated in space, the difference between these materials can be accentuated by moving one of them in space. In this example, a simple clockwise path is proposed. The spatial movement of the drums and the synth-bells create interest and more independence between the two musical materials.
A different, more surreal, treatment is to move the synth-bells and the drums around the head during the modulation, going back to the starting point once the modulation is over. Spatial movement and modulation work in tandem by conjunctively completing a cycle.
Rhythmic illusions, however, are not necessarily carried out by a percussion instrument, as pitch substantially affects how a rhythmic sequence is experienced. This notion can be clearly exemplified with a Riff.
In the following example in Figure 5, a) an 8 note pattern is set to b) a 3/4 bar rhythmic pattern. The rhythmic pattern never changes but since the melodic pattern has eight notes one tends to hear the first C as the beginning of the phrase, giving us the illusion of a changing rhythm.
5. 83. Bismuth: a modest approach to spatial music
My first approximation to spatial music composition was 83. Bismuth, a piece for quadraphonic speaker arrangement and semi open headphones.
The title was chosen as a reference to the cyrstals of bismuth (Figure 7), the chemical element number 83 in the periodic table. I have always been fascinated by the colourful and intricate shapes that this element generates when turned into a crystal; spiral rectangular patterns with a mesmerising rainbow hue, naturally derived from its atomic arrangement.
Inspired by this, I decided 83. Bismuth to be a composition based on patterns and on the distribution of these patterns around the speakers and headphones.
83. Bismuth was composed employing Logic Pro-X and DearVR Music. The main musical instrument I employed for this piece were arpeggiators, synthesisers which repeatedly play a determinate sequence of notes. In this piece I began to explore the different ways we understand the relationship of these sequences depending on their distribution in space. Something as simple as changing the positioning of certain notes in space strongly changes the way a sequence is perceived, in other words, music is transformed when spatiality is transformed.
5.1 Structure
83. Bismuth has a total duration of 10”30’ and consists of 5 main parts:
i. Patterns
ii. Chords in space
iii. Relationalities 1
iv. Relationalities 2
v. Spatial progression
The first section of 83. Bismuth, Patterns is built on a repeated pattern on a synthesizer played only through the headphones and dichotically separated (Figure 8). Because of the total absence of spill, dichotic sounds (hard panning) in headphones generate a very harsh effect of separation, an effect which may be almost unattainable with any other reproducing media. In this first section of the piece, I benefited from this separation for transforming the perception of patterns. By simply shifting the position of the notes of a certain pattern between the ears, a powerful effect of variation is obtained.
Later in the section, using DearVR Music I arranged an octatonic arrangement simulation, the eight notes of the arpeggiator were now located around the head of the listener. While being aesthetically appealing, the effect of pattern separation was not nearly as effective as the hard panning.
The second section, called Chords in Space, deals with two main aspects: the unique sensation of immersion achieved with the headphones, and the objectification of a musical material caused by literal repetition. This section is built with a three-chord pattern which coincide with the harmony of the previous section.
One of the mixing settings I tried for this section was to place the dry signal of a synthesizer in the headphones and the reverb (and only the reverb) of this same synthesizer on the speakers. On my personal experience, I believe the sensation of spaciousness achieved with this setting to be unparalleled. Hearing a direct sound spreading from the headphones out to the whole room is effective for generating width. With this setting established, I decided to occasionally remove the dry signal coming from the headphones, leaving out only the wet signal (the reverb) coming from the speakers. This created an interesting effect of dislocation as the instrument which is the apparent source of reverberation is removed. Visually, this effect would be equivalent to removing an object which casts a shade in a surface (Figure 9).
Further in the section, the chord coming out of the wet signal (of the reverb) is changed, reinforcing the sensation of dislocation and introducing the next section of the piece. Gradually, this new chord is sustained and starts to travel from the speakers into the headphones while the previous chord pattern does exactly the opposite. With this movement I was trying to recognise the moment when the perception of a sound signal shifts from foreground to background. In this case, the chord pattern, the sound signal with the most activity, even when it is sent outside to the speakers, is barely perceived to be a background signal.
For the third section, Relationalities 1, I tried to make a re-exposition of the theme by bringing back the arpeggiators. This time, the goal was to explore the illusion of coupling pitches depending on their location in space. As in the first section, I broke up an arpeggiator between the left and right channels of the headphones, then, using DearVR Music, I changed the placement of certain notes, moving them slowly between the ears. The notes which are dislocated from the pattern slowly become more relevant and independent, we can localise them and recognise them fully. As they approach the other ear, these notes suddenly fade away and get lost inside the pattern. The effect is similar to dropping a single ball into a pool of balls.
In the next section, Relationalities 2, I aimed for achieving a similar effect, this time using sounds with long sustain, slow attack and slow decay. For this section I selected six two-note intervals, covering the twelve tones of the chromatic scale (Figure 10):
These intervals were selected and designed for generating a bitonality between AbMaj7 and F#Maj7, with Asus4(add9) as an additional colour. In this section, each interval is set to have its own unique intermittent volume and movement in space between headphones and speakers, generating a soundscape of waves around the head of the listener. The goal of this setting was to focus on the different combinations of notes created by their own movement in space, just like moving numerous spotlights and combining their colours on a surface.
This effect can be heard but it is rather blurry and requires a great effort for it to be perceived. The reason behind this may be that the spatial movement of the sounds in space overcasts the resulting combinations of harmonies, in other words, movement is what captures most of our attention. This may be related to the principle of good continuation of Gestalt psychology. This principle is evident in the coloured circles shown before, in which three overlapped circles are perceived, rather than seven segments of different colours.
The piece closes with Spatial Progression, a meditative-like segment constructed with one sole cluster which is iterated 6 times. This part is quite simple, and it implies starting with the cluster sounding through the headphones and gradually spreading out to the speakers; the notes of the chord are sent to a different speaker, and with every iteration, the intervalic arrangement of the notes change.
The cluster is a combination of GbMaj7 and DbMaj7; the notes of this cluster are spread out to the speakers and the intervalic arrangement progresses from dissonant to consonant with every iteration (Figure 11):
The objective of this part was to investigate whether it is possible to create a sense of progression or cadence using spatial movement only. The result of this effect in this piece is rather satisfactory, the different intervalic arrangements change the way the chord is perceived because of the changing intervalic distances and the various beatings and pulsations provoked by the frequential interaction between the notes. The idea is analogous to orchestrating a chord in different arrangements of instruments, however, in this case, the only factor changing the sonority of the chord is space, as the timber remains always the same.
I think this idea has a lot of potential for further development. Even though a change in sonority is perceived, I believe that a full sensation of progression or cadence was not yet fully attained. The notion of whether it is possible to achieve cadence with spatiality is a recent field of study and was investigated by Luca Danieli, Maria Witek & Christopher Haworth in their article Space, sonic trajectories and the perception of cadence in electroacoustic music.
5.2 Technical set up
83. Bismuth was first presented during the preparative sessions for my Professional Integration Activities. During this session, I played the piece to three friends of mine in room 6.78 of the Royal Conservatoire.
The audio equipment I employed for this performance was the following:
Genelec speakers of Room 6.78
- RME interface
- Computer
- 3 Sennheiser HD 206 headphones
- 3 minijack extensions
- Behringer HA400 headphone amplifier
- One jack cable
I connected my Computer to the RME audio interface of the studio, then, In Logic Pro X, I routed the sound channels to either the speakers or the headphone output. For having multiple listeners, I used the Behringer HA400 headphone amplifier to split the headphone output signal into three headphones. Finally, for allowing movement to the listeners, minijack extensions were added to cables of the headphones.
The following audio is a binaural adaptation of 83. Bismuth.
5.3 After thoughts
The composition of 83. Bismuth was challenging and it required a lot of bravery (and a bit of carefree attitude) for me to even start it. This work confronted me with new ways of understanding music, for now I was dealing with the parameter of space, a factor which was entirely unknown to me, and which opened a vast field of possibilities.
Because of this, I chose my musical materials to be very simple to bring spatiality to the foreground, as my teacher Yannis Kyriakides pointed out in class: "for a certain parameter to come to our attention, others need to be simplified".
I find the results of this composition to be very satisfactory mostly because of the way my musical thinking was transformed during the process. Every new musical idea I had was now subjected to spatiality, and with this new mindset my creative process was transformed until the point in which I began to conceive each idea with spatiality as an integral component, rather than adding up spatiality as an additional layer or a post-processing element.
I can say that 83. Bismuth was mainly a experimental piece, for I was mainly trying out materials and ideas without any certainty of achieving a specific result. The work with this piece set a clearer basis of spatiality for me and let me recognise that there is still room for the concepts and musical ideas I employed to be further developed; this means that now I could go beyond experimentation and add a compositional layer to my ideas.
The discoveries I made with this piece led to the conception and composition of 10. Neon.
6.2.4 Uncertainty principle
Source functions:
- Surrounding speakers: reverb from synthesizer accents
- Middle speakers: synthesizer accents
- Headphones: bass pedal / theremin melody
This brief section serves as a preparation for the upcoming material and as a release from the musical density of the rest of the piece.
In this small segment, the aim was to diffuse reverberations between the speakers and the headphones. While the synthesiser accents continue, a theremin gradually appears in the headphones. The theremin's spatiality (produced with digital reverb) is such that it appears to be coming from outside the headphones and to be emerging out of the synthesizer accents (played in the Middle speakers).
6. 10. Neon: travelling further
10. Neon was my second exploration of working with headphones and loudspeakers. It was also the piece I presented for my Master's graduation at the Royal Conservatoire in The Hague.
In this chapter, binaural adaptations are used to exemplify the different sections of the piece.
6.1 Concept and set up
10. Neon is a spatial-audio installation composition for speakers, headphones and online streaming inspired by the Non-simultaneity Principle of the Special Theory of Relativity. The title of the piece refers to the chemical element Neon, number 10 in the periodic table.
The spatial set up of the piece is inspired by the atomic configuration of Neon as depicted in the model by Niels Bohr: the surrounding speakers represent the electrons; in the center, a subwoofer and a headphone splitter represent the nuclei of the atom (Figure 12). The headphone splitter in the center, however, merely serves as a technical backup for the audience. This aspect is explained further in this chapter.
10. Neon is comprised by 8 sections. Since the piece is a loop without starting or ending points, the sections are not numbered and hold no structural hierarchy:
• Linear combinations
• Superpositions
• Spherical harmonics
• Uncertainty principle
• Covalent bonds
• Electron transitions
• Orbital clouds
• Probability densities
In every section a particular instrument and musical function is assigned to each sound source. Eg:
Linear combinations
- Surrounding speakers: bass arpeggiators
- Middle speakers: drums
- Headphones: Melodies and chords
Besides providing the music with a solid structure, this choice was made for benefiting the purity of the sounds. When multiple sounds are played through a single speaker, they share the same physical space in the sound wave, this means that their frequencies overlap and interact in the cone of the speaker. This can cause masking (where louder frequencies cover softer ones) and intermodulation distortion (unwanted frequencies created when multiple tones interact).
By reducing the number of sounds sent to a speaker, there is less frequency overlap and competition. This results in an increased clarity, as each sound can be heard more distinctly without interference. Essentially, less sounds means less information, allowing the details and texture of each sound to become more perceptible. This way of distributing sounds among speakers resembles the way musical material is spread among a group of instruments and provides the music with more depth.
The music of 10. Neon is mainly based on repetition and it employs the use of sequencers and arpeggiators. Repetition grants the listener with the space to try different modes of listening and allows for exploring different spatial locations for experiencing the music. Materials built with arpeggiators are very effective in a spatial setting, since by spatialising the melodic patterns among the speakers, different pitches and rhythms acquire prominency, influencing the perceived down beats of the music.
6.3.1 Linear combinations
Source functions:
- Surrounding speakers: bass arpeggiators
- Middle speakers: drums
- Headphones: Melodies and chords
The main concept on Linear Combinations is the coexistence of two musical layers which fluctuate between being perceived as connected or disconnected from each other. The challenge of this section was to create musical materials which were simultaneously self-sufficient (having full musical character on their own) and sparse (for not obstructing the other musical layers).
In the Surrounding Speakers, a bass synthesizer plays a rhythmic sequence in clockwise motion, gradually growing in intensity. In the headphones, two musical motifs generate contrast by suggesting different time signatures and tonal centers that those of the bass synthesizer. In the Middle Speakers, a kick and snare pattern glues everything together with a rhythmical mid-point between the materials.
The bass synthesizer pattern, is in pentatonic mode so that it is tonally ambiguous and different harmonies can be added on top. The melodic pattern in the headphones is designed to be tonally clear and to constantly shift the rhythmic perception of the underlying pattern of the bass synth. The chord accents, also in the headphones, are derived from the bass pattern and prepare the musical material of the next section.
The instrumental functions of the sound sources are sustained throughout the section, however, some echoes from the melodies of the headphones are sent to the Middle Speakers for generating a more integrated sonic atmosphere.
6.3.2 Superpositions
6.3.2.1 Superpositions A
Source functions:
- Surrounding speakers: chords and reverberations
- Middle speakers: drums
- Headphones: chord and reverberations
In Superpositions A, the previous chord pattern of the headphones becomes protagonist and is fragmented and dislocated between the Surrounding speakers and the Headphones. To add a sensation of spatial ambiguity, an interspersed sequence of small, medium and large reverberations is added to the chords.
The harmonic sequence and the spacing between the chords remain untouched, however, the tempo of the sequence is different in the headphones than in the speakers, deriving into a rhythmic interplay. The idea behind this was to create a two overlapping musical timelines with different speeds; the listener can pay attention to the speed of the chords in the headphones, leaving the speakers layer in the background–or viceversa.
The distribution of reverb among speakers and headphones is highly effective for generating an apparent multiplicity of spaces.
6.3.2.1 Superpositions B
Source functions:
- Surrounding speakers: chords
- Middle speakers: silent
- Headphones: drums and bass
Superpositions B continues with the same chord pattern, now in a different key. The concept of this segment was to explore the way we relate multiple sounds (and musical materials) depending on their location in space.
The headphones present a rhythmic drum-and-bass pattern distributed binaurally in the headphones, going "around the head”. The chord pattern, is now distributed among the Surrounding speakers in a spatial sequence. During this section, the spatial positions between the chords in the speakers and the drum-and-bass fluctuate between coinciding and not coinciding, generating variable degrees of connection amongst the materials.
6.3.3 Spherical Harmonics
Source functions:
- Surrounding speakers: counterpoint / reverb from synthesizer accents
- Middle speakers: synthesizer accents
- Headphones: drums >> bass pedal
Spherical Harmonics follows a similar principle as the previous section, this time, with counterpoint.
For this segment, a 3-part counterpoint was distributed amongst four speakers; each part mainly built with adjacent notes. These continuous lines were distributed in space so that every speaker plays one note of the melody. With three simultaneous melodies distributed in this way, this results in disjunct melodies played in every speaker.
In parallel to the counterpoint, a melodic sequence based on the motifs of Linear Combinations are played in the Middle speakers. For granting these accents with spatiality, reverberation was added and was sent to the Surrounding speakers.
The spatial distribution in this section was made for exploring the way we hear and perceive melodies. Does our brain connects two notes based on their spatial proximity or in their pitch proximity? As this segment demonstrates, melodic lines tend to overcome spatial distribution. Even when one tries to listen to the disjunct melodies coming from one speaker, the continuous melodies prevail and take most of our attention. The notes which are closer in pitch are easily connected and perceived as a unified melody regardless of their position in space.
6.3.5 Covalent Bonds
Source functions:
- Surrounding speakers: chord sequencers
- Middle speakers: synthesizer accents >> silent
- Headphones: theremin melody / drums
Covalent Bonds is an investigation into polyrhythmic perception. This section is built with two layers of chord sequencers playing the rhythmic pattern shown earlier (Fig. 14). Both layers differ in either their starting point in time or in their tempo, thus producing a rich polyrhythmic texture.
Each of the two chord sequencers was sent to one half of the octaphonic speakers, dividing the space into two sections (Fig. 15):
6.2.6 Electron transitions
Source functions:
- Surrounding speakers: bass, drums and synth melodies
- Middle speakers: harmonies
- Headphones: resonances >> arpeggiators
The most rhythmically complex segment of the piece is based on the principle of tandem work between motion in space and rhythmic modulation, discussed in chapter 4.3 Rhythmic Illusions.
Three instruments: bass, drums and synth melodies, are positioned in one sole speaker. Only when a group of instruments do a rhythmic modulation they “travel” around the speakers, coming back to the starting point once the modulation cycle is completed. The rhythmic modulations during the section have varying cycle lengths, thus producing different moving speeds in the instruments.
In the headphones, resonant harmonies derived from the material in the speakers provide the section with growing intensity. The material in the headphones is designed to avoid excessive density that might distract from the rhythmic modulations. Close to the end of Electron Transitions, fast arpeggiators gradually appear in the headphones, preparing the material for the upcoming section.
6.2.7 Orbital Clouds
Source functions:
- Surrounding speakers: arpeggiators
- Middle speakers: bass
- Headphones: arpeggiators
Orbital Clouds is based on the principle of Stream Integration explored in chapter 4.4 Melody.
The section is built with three arpeggiator layers distributed in the speakers, and dichotically in the left and right channel of the headphones. In the same way as in the melodic channeling experiment by David Butler, three continuous patterns are interspersed between the three sources, resulting in three disjunct patterns (Fig. 16).
6.3.8 Probability Densities
Source functions:
- Octaphonic speakers: bass arpeggiator
- Satellite speakers: silent >> harmonies
- Headphones: resonances >> synthesizer chorale
Probability Densities is the last section before the loop restarts, gradually recovering the musical material and source functions of Linear Combinations.
In this section, the speed of sound is brought to the fore. In the Surrounding speakers, a fast and sharp arpeggiator is distributed in a disjunct sequence. When standing in the middle of the speakers, the rhythm of the arpeggiator is heard clear and steady, however, when one moves away from the center, the micro differences caused by distance differences and room reflections affect the perceived rhythm of the arpeggiator, resulting in a perceived chaotic irregular texture.
After this fast texture, the arpeggiator gradually slows down and a synthesizer chorale plays in the headphones. This chorale, starting at an imperceptible volume, slowly grows in frequential content, reaching a high intensity point until the arpeggiator in the speakers is almost entirely covered up.
This idea of this fragment was to explore the thresholds in which a musical material shifts perceptually from foreground to background and viceversa. In this case, the opposing spatial and musical characteristics of the chorale and the arpeggiator generate a fluctuation on the attention of the listener, where the materials go back and forth in their musical prominency.
6.4 Dealing with unsynchronised layers
As mentioned earlier in the chapter, the decision of employing online streaming for the headphones track led me to compose the music taking latency into account.
Online streaming presents latency that varies from 15 seconds up to a minute depending on factors such as internet connection speed, buffering, website service, rendering, etc. For the performance of 10. Neon, this meant that the timing of the streamed headphone track would vary for each member of the audience.
To maintain rhythmical and tonal coherence under these conditions, the following principles were employed:
1. Complimentary tempi: Materials which have differing but mathematically related tempi are resistant to variable starting points while maintaining a solid and perceived relationship between the two.
Eg: Layer A at 100 bpm + Layer B at 75 bpm.
Rhythmic relationship (Fig. 17):
2. Fast tempi: Fast paced materials can easily fit over almost any other rhythmic layer. The large number of temporal events increases the probability of coincidences (or apparent coincidences) between the two rhythmic layers (Fig. 18):
3. Differing BPM: One consequence of latency which was avoided in this piece was to have two consistently unsynchronised layers (Fig. 19):
When one of these layers is differed by 1 BMP, synchronisation points are ensured, regardless of the starting point of either of the layers (Fig. 20):
Special thanks to Orsyola Toldi, Leslie Smucker and Simone Sachi for helping me to make this installation possible.
The following video is a fragment from the performance of 10. Neon, recorded in Studio 6 of the Royal Conservatoire on June 11, 2025.
6.6 Listening to 10. Neon
Binaural and stereo + headphones adaptations of the piece are available on my website:
https://www.blarewolfofficial.com/#works
6.7 After thoughts
From an audio production perspective, one very satisfying aspect of assigning a specific musical function to each sound source was that there was no much need for applying equalisation, filtering or compression to the sounds. Since there is no sonic hierarchies in 10. Neon, each sound is allowed its own physical space and doesn't need to be 'fitted' among others, as is typically required when mixing for the stereo field.
Focusing on a critical evaluation, I observe that more attention could have been payed to the frequential aspects of the sounds. The synthesisers and timbers in this piece have evident musical functions, however, some of them may carry too much more frequential information (distortion, modulation effects, noise) which may be detrimental for achieving clarity and contrast within the musical structure.
On the other hand, I consider that the set up of the piece, in which the audience is free to move around, is a substantial enhancement for the experience of 10. Neon. As Enda Bates points out, one main concern of electronic music performance is that it often lacks the visual element of live performed music. Adding any sort of movement to an electronic music piece may be an effective substitute for the live aspect of traditional music and grant the work with a valuable layer of physicality.
For practical and compositional reasons, the numbering for the speakers in 10 Neon is continuous clockwise, rather than the conventional octaphonic numbering system (Figure 13).
Aesthetically, 10. Neon is inspired by the characteristic sounds, harmonies and melodies of EDM. Aside from a personal preference, this choice was made with the intention of taking advantage of the semantic meaning of these familiar sounds. Melodies, rhythms and timbers which are so familiar (and maybe somewhat cliché) may hold extramusical significances and build aesthetic expectations in the listener. In 10. Neon, the melodies and rhythms constantly suggest a groovy tune without never actually establishing it.
Regarding form, 10. Neon is a 26 minute-long seamless loop without delimitate start or end points; in this way, the audience can come in and out of the installation at will and start listening to the piece at any given moment. In the same lines of relativity, the audience is encouraged to move around the space for exploring different acoustic perspectives; there is no sweet spot for this piece and any position is equally valid.
Accordingly, the music in 10. Neon follows the same principle: musical materials with different tempi and time signatures are overlapped with each other generating ambiguity on the “true tempi” or “true time signature” of the piece.
Just as in 83. Bismuth, in 10. Neon the notion of prominence of musical materials is inspected. In short, a musical material may be less dense in information, but its magnitude may provide it with more perceived size, and hence make this material more relevant to the listener. With this in mind, the sound magnitude generated by the vibrations of the speakers is utilised to enhance the prominence of certain materials, generating a dichotomy between the sounds coming from the speakers and the sounds coming from the headphones.
10. Neon, as well, is an exploration of the thresholds of connection between musical materials. As presented in Tables 1 and 2 in chapter 4, by modifying the spatial properties of the materials, various levels of musical relationships are obtained.
6.2 Online stream
Initially, 10. Neon was intended to be an installation build with speakers and a headphone station in the center; the music in the speakers and the headphones would come from one sole audio mixer.
Even though this setting allowed for full musical synchronisation between the speaker and headphone's musical layers, it had the huge drawback of the headphone cables, which significantly obstruct the audience’s movement. Unfortunately, wireless headphone systems were not an option since, besides being high-priced, they are not capable of offering full synchronisation.
I am very grateful to have consulted Aurelie Lierman, who, after a quick 15-minute talk, suggested me to forget about the full synchronisation aspect and prioritise what I wanted the most in the piece: freedom of movement for the audience. This derived into the idea of streaming the headphone music track online, in this way, people could listen to the piece using their smartphones and headphones and move freely around the space. Since it is likely that not all the members of the audience have the required gadgets for listening to the piece, a headphone splitter is left available at the center of the installation.
Leaving aside the full synchronisation between the two musical layers added an additional level of interest to the piece. This topic is explored further later in this chapter.
6.3 Musical structure
The main structural backbone of 10. Neon is the binary pattern:
1 1 1 0 0 1 1 1 1 0
This ten-digit sequence is translated into different musical patterns throughout the piece, mainly, as the following rhythm (Figure 14):
In this way, the listener can travel from one rhythmic layer to the other. The chord sequencer which is closer to the ears of the listener will tend to be perceived as the “true beat” of the music; this perception can be easily changed by the listener when moving to other locations in the space.
The theremin in the headphones, serve as a connecting line during this section, having solely this musical purpose. The intermittent drums, on the other hand, are intended to serve as a navigation guide for the listener’s attention inside the polyrhythmic texture. The drums in the headphones are hard-panned, traveling between the left and right channels. The movement of the drums in space easily drag the ear of the listener and move their attention from one side to the other, shifting their focus between the rhythmic layers of the chord sequencers in the speakers.
The objective behind this idea was to create a soundscape of appearing and disappearing melodies in the ears of the listener.
This section presented a slight problem of balance. At certain moments, the sound quality of the arpeggiators in the headphones (sharp, clear and dry), tends to hinder the arpeggiators played in the speakers. For the effect of Stream Integration to be fully perceived in this section, the listener needs to be standing next to one speaker at a distance of around 40 cm. More experiments regarding timber have to be made for this idea be more effective.
Orbital Clouds finalises with a chord crescendo in the headphones, preparing the material of the next section.
4. Long transitions: The most simple solution when working with latency would be to give the musical layers enough time to catch up with each other. In 10. Neon, the majority of transitions between sections last a minimum of 30 seconds.
6.5 Performance and Technical set up
10. Neon was presented at Studio 6 of the Royal Conservatoire of The Hague during the Master Graduation Festival on the 10th and 11th of June, 2025.
The stage plan for the installation (Figure 21), worked out by Simone Sacchi, was arranged to ensure a safe, unobstructed environment for audience movement.
The streaming of the headphone track was done through Mixcloud. Mixcloud is a payed service for musicians and offers high resolution audio streaming. The quality of the audio during the performance was excellent and did not present any technical problems.
For complimenting the headphone track streaming, I created a video with a goniometer metering, which grants the listener with an enhanced experience of the spatial aspect of the piece (Fig. 21):
7. Conclusions
The goal of this research was to investigate how spatialisation may influence the relationships of musical materials and hence, the way pitch-and-rhythm based music is perceived. The cited works on this paper, covering physical, psychological and aesthetic approaches, demonstrate that spatiality is intrinsic to every musical experience and that music and space are inseparable. Being so, shaping spatiality directly affects the perception of musical content.
Is worth noting that spatialisation in pitch-and-rhythm based music has been a common practice in the recording discipline of popular music ever since the first recordings in cylinder phonographs in the 1890s. Placing the sounds in a stereo mix is the most usual practice for producers and audio engineers, however, this localisation is mainly aimed for achieving clarity and intelligibility of the instruments and not for moulding their perception within the music. As relevant as it is, localisation in audio production has not developed a defined spatialisation vocabulary that goes beyond the clear separation of the sounds. Similarly, spatial music is mainly focused on the frequential aspects of the sound and it often does not explore how pitch, harmonic and rhythmic relationships are shaped by their movement and localisation in space.
I infer that the reason behind this is that pitch and rhythm tend to draw the listener’s attention off the intrinsic contents of the sound, and probably even off their location in space, the two more crucial aspects of spatial music composition. I wonder if, through the ubiquity and development of spatial-audio technology, further complimentary relationships between pattern-recognising listening and morphological listening could be explored. As previously discussed in this work, both tonality and spatiality can work in tandem and reinforce each other; both can interact without cancelling each other out. However, the coexistence of both listening modes will be more effective if a balance of the amount of information between the two is pursued.
In a similar way, I observed that little attention has been payed to the composition and analysis of music which happens both in speakers and headphones. Headphones are a rich topic and a vast amount of research has been done for investigating their social, physical, psychological and emotional effects on the users. This supports the notion that headphones offer a promising field for artistic exploration and, by being headphone-listening such a singular phenomenon, it can work as an effective experiential contrast when combined with speakers, as confirmed by works of artists like Yannis Kyriakides, Justin Bennett, Ji Youn Kang, Noah Vawter, etc. Further, this may be a proper time for investigating this combination as the current technological trends for enhancing headphone listening with devices as Apple Spatial Audio and Dolby Atmos are encouraging artists and music producers to integrate spatiality into their creative process.
When combined with speakers, headphones offer a significantly different music listening experience. By being so contrasting to speakers in magnitude, proximity, and frequential range, headphones can constitute an additional sonic layer in a spatial music composition. Different headphones may provide different levels of separation from the “external sounds” of the speakers, and all of them grant equally interesting possibilities for musical narratives. A fully dualistic experience of two musical worlds can be achieved with noise-canceling and closed-back headphones, where listeners would need to take off their headphones to know what is happening outside their bubble. Semi-open-back headphones grant the listener partial isolation, filtering out some frequencies from the outside and generating a blurry mix between the two worlds. Open-back headphones, providing almost no isolation, serve for complex interplays of close and distant musical materials with greater sound localisation clarity.
Regardless of the level of isolation, headphones deliver the singular experience of having sounds attached to one’s ears. When incorporated with movement, this brings the listener the possibility of trying out different head orientations, locations, and paths for exploring musical combinations between the headphones and the speakers. Moreover, this allows each listener to have a fully individual experience of the music, as no two people can occupy the same place at the same time. From a creative perspective, this invites the composer to be economical in the generation of material, as this material will be moulded by the audience in the space.
Moreover, as confirmed by numerous investigations, the dichotic separation that headphones provide—unachievable with any other medium—significantly influences the perception of musical materials. Hard-panning provides a full multilayering of sounds, as these are not combined in a room, and no reflections are blended together; the mixing of these signals happens entirely within our brains. As presented in earlier chapters, dichotic listening offers alternative possibilities for the composition and perception of contrapuntal materials, with the perceptual effects of stream integration and stream segregation as the main guiding parameters.
Finally, the composition of spatial music for headphones and speakers (or any other external sound source) brings a reflection on the ubiquity and significance of these devices. How much are we isolating ourselves from others? How much can headphones make us feel more comfortable in a crowded space? Do they really bring us closer together? Spatial music pieces and art installations with headphones may be an interesting exercise in how to turn isolation into a shared social experience.
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