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3. Live Coding the Global Hyperorgan
© Mattias Petersson, 2025
Patch 7: Sinew0od for Halldorophone
The Sinew0od system has been used as a starting point in an investigation of how translation and transcription can be used as artistic methods to understand and compose with the different agents within a cybernetic system such as this.
Building further on the pilot study and transcription for the bass clarinet, I wanted to test how the Sinew0od system responded to a string instrument and got the opportunity to work with a Halldorophone, temporarily on loan to EMS – the electronic music studio in Stockholm.
This piece was a result of a series of workshops, carried out at EMS between January 23-27, 2023. The instrument was created by artist and designer Halldór Úlfarsson, and, besides being a string instrument somewhat reminiscent of a cello, it also incorporates its own internal feedback system with discrete electromagnetic pick-ups and volume controls for each string with a transducer speaker inside the resonant body, enabling self-oscillation. It also has four resonance strings below the fret board, with separate pickups and discrete volume controls for each.
The Transcription
Together with the cellist My Hellgren, who had previous experience with this instrument, I conducted a series of filmed workshops – similar to the previous ones with Petrini and Ek – where we experimented with different types of interaction with the Sinew0od system. Again, a functional translation approach was used in the transcription process. The electroacoustic Halldorophone is a very different instrument from the previous wind-based ones, and many of the original techniques needed a rethinking.
An initial question was how to deal with the function of multiphonics in the original composition. There are indeed such effects to be explored on stringed instruments, and they can be very effective on, e.g., a cello. However, similar to the bass clarinet, these multiphonics tend to sound like dyads, with a strong fundamental and a dominant upper harmonic.
The complex chordal quality of the Paetzold, which worked particularly well within the Sinew0od system, gets lost here. This led to experimenting with the internal feedback and by making glissandi on the strings while trying to find resonant nodes. Eventually, the multiphonics were functionally replaced by a hit on the fret board, followed by a glissando up or down, mimicking the crescendo and diminuendo gestures in the original score, although the outcome was sonically very different. Ultimately, we aimed for creating a 'wobble' sound in the internal feedback during the glissandi, but this was quite unstable and worked almost exclusively on the lower notes. This was probably due to the inherent inertia and the settling time of the internal system, in combination with the resonant frequencies of the body. In general, the internal feedback turned out to be more effective on the lower strings. We aimed for calibrating the feedback levels so that it had to be excited using the bow, a hit on the fret board, or a pluck to start.
The Patch
We also made use of the possibility to insert the volume pedal directly into the mixer of the Halldorophone, giving Hellgren control of the total level of the internal feedback. I made some initial tests by inserting other parts of the Sinew0od system into the instrument's feedback system, e.g., patching the output of the pickup mixer to the Mackie mixer connected to the Sinew0od system's speakers, but all these tests turned out to be either ineffective or were just adding unnecessary, unrewarding complexity to an already complex system. The simpler solution of inserting only the volume pedal at this position instead seemed to change the focus from not knowing what was doing what to an embodied understanding of the system, where a feedback pitch that went out of control could be immediately balanced with the foot pedal.
A Second Human Agent
Due to the fact that the complex internal feedback system demanded Hellgren's full attention and also because it seemed interesting to add another human agent to the system in regard to the exploration of Sinew0od within this research project, I performed live on the Sinew0od feedback control system together with her. In practice, this involved balancing the external system with the Halldorophone's internal system, by controlling the mix of the two, moving forward with the switch pedal according to the cues in the score. Thus, the feedback controller here was outsourced to me as another human agent. Hellgren sometimes expressed that it could be difficult to know which feedback system was at play at the moment, which we agreed was an interesting musical feature of this piece, but also made it more demanding to play. When performing, my task was to balance the Sinew0od system's feedback and the feedback controller drone coming from the Max patch to modulate and control the internal system within the Halldorophone. Furthermore, the feedback controller drone was transposed an octave up because it responded better with the internal resonance of the instrument. These responses could be clearly heard as modulating the instrument, especially in the beatings and wobblings of the glissandi and the fermatas, and sometimes it even caused the Halldorophone to change the feedback pitch. It was not always stable, but sometimes the whole Sinew0od system felt like a feedback controller for the Halldorophone system.
The Score
Departing from the same cantus firmus and the melodic material derived from the EMP Triangle as in the original version (outlined in the appurtenant book on pp. 126-128), I quickly realized that simply playing the pitches cello style was functionally very far from the silent key presses and modulations of the feedback, which occur in the Paetzold and clarinet versions. As soon as a string was pressed on the fret board, the internal feedback became a factor. Instead, I wanted to keep the strings as open as possible, thus susceptible to the externally added feedback, induced by the Sinew0od system. The solution was a scordatura tuning based on the cantus firmus. Thus, the strings were tuned to B, Eb, C# and Bb, going from the lowest to the highest string, and the resonance strings where tuned a fifth up to F#, Bb, G# and F respectively. This allowed all the notes in the cantus firmus, and thus all phrases derived from it, to be played as natural harmonics (see the score page above where the cantus firmus is presented in the first bar).
The 'Inhale!' events in the original score were replaced by longer fermatas, freely exploring the characteristic, wobbly notes of the Halldorophone. These occur at certain nodes of the string, where the internal feedback and pitch resonate well with the system, and beatings can be achieved by moving the finger slightly on the fretboard.
Similarly to the bass clarinet transcription, the original's fermatas, where Petrini cupped her hand around the microphone, could not be accomplished effectively here. The microphones used here were a matched pair of Neumann KM-184, positioned approximately at the same distance as the Philips SBA-1500 feedback speakers. However, the general musical idea was always to introduce something different that somewhat disturbs the form in these bars. This opens up for more creative thinking, and in the end, the musical gesture was replaced by a quick bow, exciting all the resonance strings, followed by a fade in with the volume pedal, to bring them in to the mix, and then a scratch tone on the bridge of the regular strings to color the feedback and to keep the resonance strings ringing. The aim here was similar to the original: try to find a nice timbre and then move on (and this subjective 'niceness' is up to the performer to decide).
The video above was filmed during the final hours of the workshops at EMS with cellist My Hellgren, held between January 23-27, 2023.
The Halldorophone.
Photo by Estheryrthorvalds - Own work, CC BY-SA 4.0.