Given the understandable situation that while, in general, most people have little interest in understanding the underlying acoustic principles of these unusual sounds, the Baschet history of public participative sound sculpture exhibitions has demonstrated that many people, millions over decades, can enjoy them nonetheless. Even without having a clue about what is going on, and because there are no hidden wires or technologies, participants find that these unpredictable sounds are simply there to be freely played and enjoyed.
In this section we apply a Baschetological perspective to historical and traditional instruments and the recent work of experimental instrument builders. From this perspective, any instrument can be considered to be an odontophone if it uses clamped elements as oscillators and typically some sort of coupled radiator to convey the vibration to the listener. We believe it is beneficial for all of these devices to be studied according to their similarities (and differences), as relevant. We propose this according in line with the reasoning that studying the commonalities (and differences) of stringed instruments from many time periods and cultures might allow for a better appreciation of the particular nuances and subtle variations of each individual instrument.
We can consider Kalimbas, nail violins, and toy pianos to be odontophones (from a Baschetological perspective), and by doing so we gain valuable insights into their function. In all three instruments the qualities of the sounds produced are determined by the conjunction of several materials. The functions of oscillation and radiation are distributed: the sound of these instruments is dependent on the function of clamped oscillators. These clamped oscillators are not able to radiate their vibrations sufficiently to the transmission medium, so we find them coupled to a sounding board or box that adds radiating surface and filters the vibrations according to the type of material and its shape. The quality of the sound is ultimately determined by the nature of the radiators. If we change the material or shape of the radiators, we inescapably change some aspects of the sounds.
Observe the kalimba family: tines or prongs are clamped rigidly, and the resulting tension is what creates the actual pitches heard, a combination of the inherent stiffness of those metal pieces and the external tension added by clamping them. We can also change the length easily, because each prong is an individual oscillator, so changing one will not change the overall system. When prongs are plucked on their free end, the sound is transferred through the bridge to the board, which is usually able to radiate the fundamental frequencies when the wavelength is short enough and not very low. Lower frequencies require larger radiators.
Nail violins are pretty close to kalimbas, but since they are to be bowed, not plucked, we find the display to be different, adapted to the motion of bowing. This is normally in an arched configuration so individual nails can be bowed, and arpeggios or chords can be realised by changing the inclination of the bow.
On the other hand, toy pianos feature longer rods than kalimbas and nail violins. Their fundamental frequencies are far too low to be successfully radiated by the tiny sounding board of a toy piano, so we hear only certain upper overtones, which is what gives the toy piano its personality, a unique and recognizable timbre. The sound is not only defined by its primary oscillating source, but also by the radiating elements that filter out some of the spectral content present in the oscillators. The sound, then, is the product of a compound system, made of different shapes, materials, and functions.
Other Odontophone examples
Pinuccio Sciola: stone sound sculptures
We can find examples of completely idiophonic odontophones, in which there is no need for any coupled radiator, similar to many of Pinuccio Sciola's stone sculptures in which rocks are cut into thin, wide plates, liberating the “teeth” from the overall mass and creating a system of oscillators free to vibrate on one end, radiating the sound from all the surfaces of the tooled object. The vibrational modes of the stone teeth are similar to the odontophones previously presented. The interactions of all the parts are similar, and much can be learned through recognizing the commonalities and particularities in all those sound objects. Despite the fact that the teeth of Sciola’s pieces are not clamped but carved, they end up behaving like clamped elements: a node is created at the base of the tooth, and an antinode is created at the free end. The difference in pressure and vibrational amplitude between the free end and the embedded connective region determines the vibrational mode of each tooth. Furthermore, the connection of all of them through uncut gum allows for resonances to be shared among all vibrating parts. So, in our opinion, the fact that the procedure for realizing this complex system of interconnected teeth is different for the Baschet odontophones, kalimbas, nail violins, and toy pianos, does not necessarily need to override the commonalities of their vibrating behaviours. The fact that the carved shapes feature much more radiating surface allows them to be self radiating: idiophonic, thus. In other words: if we carve a big enough music box comb, we will most likely not need a radiating box. By the same logic we can also consider tongue drums as idiophonic odontophones in which the radiating surface of the cut tongues is adequate, plus the whole body works as global radiator. For us idiophony is a property of any oscillator that can radiate its internal vibrations, no matter what the shape: a suspended plate, a kettle, a metal tank, or a carved set of teeth on a stone block or a metal tank.
Harry Bertoia: Sonambient Sculptures
Harry Bertoia’s Sonambient sculptures are variations and permutations of the same scheme: very long rods of equal length, welded at one end to a heavy metal plate that operates as a gum, creating the typical differential in amplitude and pressure between the ends of the rods. Since they all share the same spectrum of frequencies, the rods create a powerful resonance, creating a deep sound. Given their length, their fundamental mode is subsonic, we can actually see and count the oscillating ratio, so what we hear consists of the higher overtones. In this sense we could say most of them are idophonic, since the sound we hear is radiated by the rods and the gum themselves, filtering out some of the lower frequencies, which remain “trapped inside.” Some of the pieces sit upon wood boxes that add radiating surface and augment midrange frequencies, in which case we might not consider those as idiophonic. The beauty of this work lies in all the different sonic textures created by the accumulation and permutation of the same kind of rods, the gathering of pieces into a sculptural group that complement each other, and the diversity of possible activations and motions that produce sounds, from swinging and swaying in rhythmical waves to spiraling, chaotically shaking, etc.
Tom Nunn: Crustacean and Lake of Trees - Part of Nunn’s spaceplates family
The Crustacean features bronze rods, straight and bent, of different lengths and thicknesses welded to a radiating metal sheet, suspended on balloons that provide insulation and radiation at the same time, since the balloon membrane is soft enough to not dampen the vibrations and transfer them into the air, as found in the early Baschet odontophones (percussion instruments and Cristals). Rods can be bowed, plucked, or stroked. The deep sound comes from the freedom of vibration provided by the stainless radiating sheet that adds its resonances in a way similar to the radiators of the Baschet Cristal.
Lake of Trees displays intricately bent rods welded directly to a radiating stainless sheet. When activated, vibrations can be seen on a layer of water on the sheet. Again, the rods are longer than they appear, so what we hear is generally the upper partials of the intricate shapes, depending on where they are bowed.
Hans Reichel: Daxophones
Reichel’s Daxophones only use one wooden “tooth” at the time but with a large number of different shapes (made of different types of wood), therefore demonstrating the importance of the shape (and material) on the sound qualities. They are designed to be bent and pressed to realise and articulate all sorts of tonal inflections; radiation is accomplished by contact mics but could also be achieved through sounding boards or Baschet-like speaker cones.
Hal Rammel: Triolin
Triolins are similar to nail violins, as the similarity of the name indicates. The structure of the Triolin is almost the same as a nail violin – metal tines fixed perpendicularly to the face of a soundboard – although Triolins feature longer prongs than most nail violins. The fundamental frequencies are never heard, only the higher overtones, particularly because they are usually and easily bowed near the base, so the fundamental is not even excited by the bowing.
Bryan Day: RotoWhisker (similar to Hopkin’s What-a-shame)
One single carbon fiber rod clamped to a contact mic is activated by being bowed and/or being contacted by the edge of a screwdriver handle, which simultaneously defines the length of the rod that is able to vibrate. Rotating the screwdriver handle can generate regular pulses and scratches on the rod, creating interesting sounds.
Simonas Nekrosius: The Octopus
Metal strips are clamped to a wooden box that radiates the sound, activated by an automated spinning pendulum that adds a degree of randomness to the sequences of sounds produced.
Constance Demby: The Space Bass
The similarities with the early Baschet odontophones from the 50’s are obvious: several round rods clamped to a gum are the primary oscillators, radiated by a stainless steel sheet – bent to modify the inherent lack of tension of a flat stainless steel sheet – that provides most of the resonances and reverberation. Rods can be individually adjusted for tuning and can be both bowed and stroke. The size of the sheet allows for very low frequencies to be radiated without losing the brightness of the tone (a quality of the stainless steel radiator). The whole vibrating system sits balanced upon a padded pair of legs to avoid leaks.
Richard Waters: Waterphone
Round rods, welded to the rim of a circular metal vessel, can be stuck or bowed. The vessel containing water can be tilted and moved so the liquid restricts and frees certain regions of the base radiating surface, modulating the sound like a “wah” effect.
We would like to conclude this list with a selection of Bart Hopkin's work using clamped oscillators (piano wire, tempered steel bands, and threaded rods) that we also consider to be in the family of odontophones:
Waterfall - metal strips clamped at one end to a frame and activated by percussion. The width of the strips allows them to radiate higher overtones directly into the air, producing a bright and unique sound. The strips are cut to specific lengths in order to tune the radiated overtones to produce 12-TET pitches.
U - an amazing piece, mastering overtone tuning and displaying an array of rods grouped in consonant groupings for a complete chromatic range across several octaves.
What-a-shame - an extremely interesting device that can be seen on the Vibrational modes of clamped oscillators section, where one can appreciate the many vibrating modes and their timbral qualities. It consists of a single round rod, partially clamped to facilitate sliding and playing around with wavelengths, whose vibrations are transferred to the amplification system through a contact mic.
Wood Butter - long rods sounding in a way similar to the big Baschet pieces we discuss here, with interesting activation of micro-percussions of tiny objects descending along their lengths. Vibrations are transferred to the amplification systhem through a contact mic.
MiagoTrod - sounds resemble the Baschet classic rods, with complex resonances arising between the two ends of the same rod, each carefully tuned. Each rod, clamped in the middle, is thus divided into two lengths, with its perceivable pitches tuned an octave apart, so no matter which end you activate, resonances are created amongst both ends of the rod. Vibrations are transferred to the amplification systhem through a contact mic. Remarkable use of weights on the ends of the rods successfully retune inharmonic overtones to create a more consonant and clear pitch.
Bong Tones - spring steel strips, clamped as in an electroacoustic kalimba, produce low tones with bright overtones adding to an interestingly rich timbre. Vibrations are transferred to the amplification system through a contact mic.
Polly - clamped tines whose timbre falls somewhere between a kalimba and a music box. Since we primarily hear the fundamental frequency of the short tines, Bart has retuned the first inharmonic overtone of each one to create a more consonant spectrum for each tine, resulting in a more defined pitch. Vibrations are picked up and transferred to the amplification system via some sort of magnetic pickups.
Mallet K - interesting case of a pair of kalimba-like instruments that, instead of radiating their infrasonic fundamental, radiate the next set of overtones when stroked with hard mallets, therefore producing a sound different from traditional kalimbas. Vibrations are picked up and transferred to the amplification system via magnetic pickups.
HHK - incredibly interesting set for glissandi of small tines literally clamped with clamps, The activation and definition of the vibrating length is determined by putting the tine in contact with the corrugated edge of a metal plate. Vibrations are picked up and transferred to the amplification system via magnetic pickups.
Bowed T-Rods - bowed threaded rods, clamped to gums formed by metal discs on wooden base (which also behave as radiators for its compound surfaces). Again, the rods’ fundamental tones are not heard because of their subsonic frequencies. Instead, we hear higher overtones when the rods are bowed within the correct region along their lengths.