List Of Acoustic Principles

Here is a list of pages that describe some musical principles that are important to making unusual instruments. This page will feature short articles describing these principles and the ways that each of these principles has a tendency to be pronounced in idiosyncratic musical instruments.


Pitch Continuum- The ability to produce any pitch within an instruments range. Instruments can be able to do this to a degree or completely. 1)

Pitch Fluid- The ability to move smoothly between pitches in an instruments range, like Pitch Continuum, but in motion between one or many pitches.
Unstable Tonal Center- Also called unstable pitch. Instruments that are intentionally unstable in pitch and make repeating specific pitches difficult. This produces a sense on instability as scales are difficult to play consistently.

Interference- Generating specific pitches that interact in unique ways Difference Tones are an example of this.

Combination Tones- When two or more differently pitched tones generate additional imaginary tones due to the way the pitches are perceived.

Interface- The way a player interacts with an instrument.

Corporeal- an instrument that cant really play any kind of discrete musical songs but instead is defined simply by the timbre and behavior of its output (think like an aeolian harp).

Tonal Maximum- When the Timbre and tuning of an instrument is taken to the maximum clarity and precision, this is a philosophy against chaotic, uncontrolled, and dissonant sound qualities in an instrument. This is the opposite of nurturing turbulence.

Tonal Chaos- The use of chaos to generate a dissonant, uncontrolled, and cacophonous timbre in musical instruments, prevalent in experimental wind instruments. This is the opposite approach to Tonal Maximum which aims for clarity of tone. The term Turbulence can be used to discuss chaotic sounding woodwinds and is the wind equivalence to Raunch which can be used to describe strings with tines. Expect further descriptive terms in the future each aiming to describe a different element of sound modification.

Terminality- The character of being on the edge of an instruments functional range, for instance the maximum length of tube to width ratio for a flute before the pitch begins to split to a higher partial. This feature is characterized by a specific kind of timbre and behavioral properties that can be described as terminal. This definition is similar to Tessetura, in that Tessatura describes the central most range of an instrument or voice, and avoids the terminal features.

Xenharmonic- The spectrum of music outside of 12 tone music. This is an organized movement to explore just intonation, alternative tuning systems, and microtonal music. The production of Xenharmonic music is often a motivating force for making idiosyncratic musical instruments.

Prepared- An instrument that has its sound temporarily altered by placing objects on or in it, for instance wedging screws between the strings of a piano as seen on prepared piano. This technique is typically temporary. This is different then the term Tinkerer, which describes more permanent alterations to existing instruments.

Indiscrete- An instrument that doesn't have easily definable separate parts.

Fungible- the property of an instrument having various parts, or the instrument itself, easily replaceable with another that are indiscernible from the original. These are often also Indescrete.

Self Contained- Instruments that are not interacted with directly by players or listeners and not intended to be accompanied in any kind of ensemble.
This is a prevalent theme in Sound Sculptures, where the sound is considered an artwork. These are frequently a Self Playing Instrument.

Self Playing Instrument- Musical instruments that play themselves using a wide variety of methods. They can be programmed to produce sounds using electronics, which makes them capable of playing any number of different outputs or can be programmed similar to a player piano using purely mechanical means. This should be considered different then instruments that are played by a specific environment (for example an instrument controlled by the wind) or that are controlled through indirect means (for example an instrument whose tone is determined by the number of people in a room).

Cyclical Music Machines are musical instruments that produce and repeat phrases that are programed into them using purely analog means similar to a player piano. Called Rotary Music Machines by Bart Hopkin, these can be considered instrument automata, and can be Self Contained musical instruments but should not be considered Stochastic because the programming method is often perfectly repeatable, and plays sounds in repetition.

Stochastic- Instruments that produce highly random sounds that have little to no detectable pattern to what they produce. Also applies to instruments that are impossible to control the sound of beyond a small amount of control of such things as volume, turning the sound on and off, and placement of the instrument. These are almost always a Self Playing Instrument and often use means to increase the level of chaos present such as Tonal Chaos.

Site Specific- An instrument that can only exist in one specific place (for example the Zadar Sea Organ), for this term the idea of it being made out of materials of that location is also relevant.

Iterative- An instrument building method that has many versions with varying changes, usually small changes. This applies to instruments made with trial and error building methods, as well as instruments that slowly evolve over time.

Ghost Tones- Secondary pitches that can be heard on string instruments that are generated by inactive sections of strings that are excited by other strings, string segments, or vibrations. This is different then sympathetic vibrations as the pitches produced are related to the pitch of the exciting vibration for a different reason. Ghost Tones are generated by the inactive segments of 3rd Bridge and Shared Resonance instruments.

3rd Bridge- When a string is divided into two connected segments with a moveable 3rd bridge. Strings of this type produce Ghost Tones.

Shared Resonance

Free String- A string that is only mounted on one side, with the other held down by a movable force such as being tied to a rock and the force of gravity acting on the string to give it tension.

Sound Generation

Modes of Vibration- the different manners which a vibration generates sound. Vibration patterns include Longitudinal, Transverse, Lateral, Torsional, and Radial.

Free Vibration- When a vibrating object is allowed to vibrate with minimal interference. This is the principle way almost all musical instruments vibrate.
This is converse to Damped Vibration.

Damped Vibration- When the ability to vibrate is dampened by some force such as a shock absorber. This is rarely used in musical instruments and has unusual characteristics to it that are under explored in a musical context.

Forced Vibration- Using mechanical means to force something to vibrate, such as controlled scraping or rasping, a feature of the Savart's Wheel, Klaxons, sirens, and scratching lenticular plastic. Instruments that use this principle often have a shrill screaming like quality to their sound, like the scraping of nails on a chalkboard. This principle is unique as the speed of the mechanical force determines the pitch produced.

Klaxon- A form of Forced Vibration where a membrane is forced to deform and 'vibrate' using a ridged wheel or disk that vibrate against a knob on the membrane. This technique can force a membrane of very harder material to deform at a set rate producing a pitch. The pitch can be controlled by the speed of notched wheel, where the notches per second coincides with the frequency.

Bowed Tongues- Bowed lamellophones, instruments with a solid bars or rods that are mounted on one side with each of these tongues bowed.



Springs and Coils


Steel Resonator- Instruments that use a large sheet of metal (most commonly stainless steel) as a resonator, this technique gives a very distinct timbre to the instruments. This is a technique used by Constance Demby, Robert Rutman, and Jan Heinke.

Conical Resonator- Using a cone shaped resonator that is mounted in the center and expands outward as a rigid or semi rigid conical form. This kind of resonator is how speaker cones resonate sound. Found on the Cristal Baschet as well as the Stroh Violin and is a common technique used by the Baschet brothers.

Timbre Modifiers

Timbre Modifier- A part of an instrument that alters the character of its sound without that part being related to the sound source, a Mirliton and rattle tines are examples of these.

Harmonic Filter- Similar to Enharmonic Filtering in that a column of air is able to selectively filter the harmonic structure of a separately generated pitch. In the case of Harmonic Filtering, when the length of a tube used to generate the filter is sufficiently long the degree that the fundamental of the generated pitch can be heard is greatly reduced, and the effect of harmonics of the tube length are strongly preferred instead, making a stepise harmonic jump between pitches where the fundimental can no longer be heard unless the pitch generated and the tube are in unison. Harmonic filtering is of course a more dramatic and advanced effect than Enharmonic Filtering and should be distinguished by the ability to still clearly distinguish the fundamental pitch of the generated tone.

Enharmonic Filter- an enharmonic filtering effect is present in most techniques that use Bisbigliando, the enharmonic filter is a secondary effect where when a pitch is generated and placed in a column of air various frequencies will preferentially be generated in response to the frequencies the tube is generating. Examples of this is humming into brass instruments or various other tubes and noting the stepwise shift in pitch even when a liquid pitch transition is generated using the voice. Another example can be done by humming into a wind instrument at a consistent pitch and noting the enharmonic filtering that happens as holes are opened and closed.

Bisbigliando- When two or more of the same (or very near to one another) fundamental pitches are trilled between one another but with various harmonic differences between the two pitches played generating a kind of timbre trill. this technique is commonly done by using different string thicknesses that are tuned the same, different material tuned the same or with various lengths of pipe that are fingered differently and tuned the same.

Raunch- “Rauchification” or “Rauchifies” is used by Bart Hopkin to define the vulgar buzzing sound that can be given to a tongue or tine when it chatters against another hard surface.

Jivari- The Braying, growling, snarling, or buzzing quality of sound produced by a string that have a bridge that produces spectral sounds, such as the bridges used in Indian instruments. 2)

Mirliton- A membrane used to modify the timbre of a musical instrument often found on woodwinds and marimbas.

Rattle Tine- is a loose scrap of metal that vibrates against a tine on a lamellophone to modify the timbre of the tines.

Movement- Using movement to alter the sound profile of an instrument. This is often done by the rapid shaking of an instrument while it is being played. This can be done by the use of moving parts next to an instrument as is seen on the vibraphone. This also includes modifying the sound of an instrument through the use of the Doppler Effect.

Moving Water- The use of a small amount of moving water inside a resonator to alter the timbre of an instrument. Popularized by the Richard Waters' Waterphone. Also found on experimental instruments by Bart Hopkin. For a wider discussion on the use of water in musical instruments see Water.

Nonuniform strings- The use of none uniform strings to produce a distinct inharmonic qualities to strings. Used to great effect by William A. Sethares' Hyperpiano.

Regulation- Regulation is relevant to wind instruments and the ways that reeds can have selective vibrating regulation applied to them in the form of lips on the reed or mouthpiece (also the way lips vibrate in a brass mouthpiece). The regulation comes in 3 forms, non regulated (like that seen on windcap instruments) where the reed vibrated uninhibited, regulated, where the reed is held by the lips and the sound produced is controlled and manipulated by lip pressure and position, and damped where the reed is crushed by the lips and only allowed to play in a muted form.

Undertone Series- A brief discussion on instruments can that play the undertone series (Didgeridoo, Large strings, Forced vibration instruments, savarts wheel, terpodione)

Idiosyncrasy- This wiki focuses on musical instruments that are made for idiosyncratic reasons.

Faceless Company- A strategy common with electronic synthesizers and micro controllers where the instruments are released without any available reference to any individual makers. This is often accompanied by lack of information on who performers, makers, and composers are using the instrument in question in promotional materials, purposefully obfuscating them for the benefit of the unknown parties. 3) 4)

Universal Music-

Alternative Music Theory-

Future Primitive-

Instrument Spiritualism- There are a great many unusual instruments made for alternative or new age spiritual purposes, these instruments are often pentatonic, play puretone harmonics, and produce long droning sounds. These instruments are made prmarily to suit a spiritual purpose. Examples include the Felix Rohner and Sabina Schärer, inventors of the Hang Drum, the instruments of Robin Armstrong, Constance Demby, Katie Grinnan, and Francisco Lupica.

Instrument Shaped Object- Instrument Shaped Objects (ISO for short) are instruments that have almost no ability to play, but has been made to look like they functions well or even like theya re professionally made musical instruments.

A term for wacky/ridiculous instrument that look outlandish but sound relatively normal (weird guitars, cigar box guitars, carrot clarinets ect.. )

Tinkerer- A person who takes an existing instrument and alters it to their needs, often done as an experiment. This is distinct from Prepared which is describing a temporary and reversible alteration, while tinkerers tend to make more permanent alterations. 5)

A term for a person who primarily improves existing instruments and attempt to maximize range and color on them (like Richard Bobo, Bret Newton, Jared De Leon, Guntram Wolf, Benedikt Eppelsheim, Wayne Stuart, Giles Brindley, and Ernesto Molinari)

lowercase- The use of very quiet materials as musical instruments. this is most often significantly amplified. There is often a material philosophy of hearing essential sounds of those objects.

Essential sound- A sound philosophy about the sound produced on an instrument being only due to a principle quality of the instruments materials itself, sounds that are essential to that object, such that the sound made is the inherent and most primal sound of that thing.

Sound Sculpture- Any sound making object that is a piece of art, often with the sound generated being considered an artwork rather then or in addition to music.

Vernacular instrument

Trash Orchestra- Ensembles that have a specific aesthetic involving primarily using found materials, improvised materials, garbage, and also have a dominate theme of eco-friendliness, environmentalism and recycling.

Improvised Instruments- Instruments made from improvised materials, frequently made from cheap and easily available mass produced instruments that have been modified. Sometimes these instruments are about essential sound and other times they are trash instruments

One Man Band

Stratification- Used to describe cultural elements (in this case instruments) that tend to exist only in specific cultural contexts or with specific groups.

aleatory- Music that is intentionally structured in a way that includes random chance operations and or indeterminacy.


Sound Synthesizer also called Electronic musical instruments.

Circuit Bending



Transmuted- When an instrument translates a type of non resonating input into sound, such as transforming light into sound, video feeds, a painting, or data ect. Instruments of this kind are typically electronic or electroacoustic.


In Need of Terms

a term for instruments that are intentionally against high craftsmanship or that avoid using difficult constructions methods, DIY instrument look, think of cigar box banjos/ guitars. This term differs from people who want to specifically create well made low cost instruments in that this aesthetic entails a certain roughness to the sound outcomes as well, the instruments in this case are intended to sound like DIY instruments.

Good terminology for the makers who intentionally remove and replace elements of expensive to make instruments in order to create low cost (hardware store) copies. This approach is dependent on reducing instruments down to sound making principles and removing unnecessary elements (in terms of that goal) and replacing them with less expensive or easier to make alternatives. For example using thin plywood instead of solid boards of spruce in string instruments or using ABS tubing instead of bored out tropical hardwoods in woodwinds. This approach is closely related to DIY instruments and often has an aesthetic look in common. This approach is also strongly counter to instrument makers who focus on the material culture of the instruments they make and the instruments are dependent on the use of culturally relative materials in the instrument construction.

the practice of making archeological recreations of musical instruments. The practice of recreating ancient instruments and attempting to work out how they were made and what they should sound like. This paractice is highly dependent on attempting to accurately make tools and materials that were used in the original archeological examples. This is a kind of experimental archeology. Examples include the works of Roberto Velázquez Cabrera, Lucy-Anne Taylor, and Susan Rawcliffe. Also the recreation of the Carnyx, Neolithic Bone Flute, Aulos and the ASTRA project.

A word for instruments made from scavenged materials, maybe something that emphasizes the tendency for the instruments to look like a conglomeration of unrelated parts/ objects assembled together. assemblage perhaps?

Something about musicians who make work that is saturated with unique and difficult to identify sound sources, making it cacophonous and filled with unfamiliar sounds (think Hans Reichel's Yuxo or some of the musical work of Bart Hopkin and Uakti. Often this style of music is eerie and creepy. A term like Phantasmagoria of sound may apply.

Sound based interventions in an environment (like Akio Suzuki 6))

Tuning-agnostic instruments
Called American Tinkering culture by Andrew Raffo Dewar in “Handmade Sounds: The Sonic Arts Union and American Technoculture”
principles.txt · Last modified: 2024/06/04 10:39 by mete
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