The Springboard by Eric Leonardson

Springboard contact microphone Eric Leonardson
The Springboard is made from everyday objects, such as a tin can lid, spring coils, pieces of wood and combs. © Eric Leonardson

Eric Leonardson invented his Springboard in 1994. This instrument is an excellent example of how the simple addition of a contact microphone can create a beautiful sonic phantasmagoria out of ordinary objects. When you look at the instrument, you can see all kind of familiar objects such as pieces of wood, combs, coil springs, a metal grill, a tin can lid and large rubber bands. The sounds produced by these ordinary objects are often of a surprisingly complex and varied nature. When listening to a recording, it is difficult to recognise the source of the sound and without any visual cues it often remains a mystery, which object produced which sound. This recording of a concert with the Springboard in 2012 gives an impression of a composition developed from the sonic possibilities of the instrument:

The contrast between sight and sound is mainly created by using a single contact microphone for amplifying all sounds produced by this instrument.  The main part of the instrument is a simple piece of wood. As the drawings by Eric show, there is a hole drilled in this board for a recessed mounting of the piezo disk. An older hole (see previous cable in the first drawing) is not in use anymore. As Eric explains: “I originally drilled into the end of the board so I could pass audio cable into the recess, similar to how a solid body electric guitar connects its coil to a jack. On the Springboard, the cable was soldered to a standard 1/4-inch jack and to the contacts of the piezo disc, inside the board. I abandoned that system because whenever I performed on the Springboard with more forceful percussive rhythmic pattern, the shaking would cause the audio plug to jiggle and momentarily break the connection, hence the audio output would be interrupted.”

Top view of the contact microphone mounted on the Springboard. Drawing by Eric Leonardson, © Eric Leonardson
Top view of the contact microphone mounted on the Springboard, the previous cable whole can still be seen. Drawing by Eric Leonardson. © Eric Leonardson


A cross section view of the mounting of the piezo disk on the Springboard. Drawing by Eric Leonardson. © Eric Leonardson
A cross section view of the mounting of the piezo disk on the Springboard. Drawing by Eric Leonardson. © Eric Leonardson


The contact microphone attached to the board. © Eric Leonardson
The contact microphone attached to the board. © Eric Leonardson

Since the contact microphone is amplifying the mechanical vibrations of the object itself, the amplified sound is filtered more than in other forms of amplification. Contact microphones give you a different sonic perspective of an object, without changing their visual characteristics. As Eric phrases: “Its ability to act as an aural microscope into unknown sonic yet entirely physical aspects of any object or material is truly exciting, if not amazing” (see The Springboard: The Joy of Piezo Disk Pickups for Amplified Coil Springs). He did not really plan to invent an instrument, but he was just looking for “a simple device for amplifying readily available objects and materials, producing a wide range of extraordinary sounds, in a way so tactile and immediate that the Springboard lent itself as easily playable” (see Eric Leonardson’s website on his Springboard, including information on all objects he uses and how to make a similar instrument yourself). But as it turned out, his search for sounds resulted in a musical instrument nonetheless.

The contact microphone seems to have initiated a process of exploring all possible sounds. The richness of the instrument is not depending of the objects themselves, or the simple method of amplification, but of a very intense investigation of all different sonic possibilities of the everyday objects used. What makes this instrument so special, is not the material itself, neither the form of amplification, but the playing techniques Eric developed: “I seldom ever hit any parts of the instrument as one hits a drum. Instead, bows, brushes, friction mallets, chopsticks, my bare hands and fingers apply controlled pressure, flexion, and friction to produce its most intriguing sounds. […] As with a stringed instrument, bowing produces a harmonically richer tone than plucking a string.”

Although nearly all sounds are produced solely by contact microphone amplification, there are a few exceptions. As you can see and hear in this documentation video of the Springboard by Joshua Baum, around 3’04” the small music box is amplified by placing it on the board and with the help of an effect pedal its sound is transposed. Musically, the use of the effect pedal seems to be an enlargement of the coloured amplification by the contact microphone: the transposition is a sonic development of the filtering caused by the amplification.

Another element is Eric’s use of the reversibility of microphone and loudspeaker technologies. In this case, he uses another piezo disk, but connects it to the output of a small radio. This piezo disk now functions as a kind of tactile transducer, and can transmits its vibrations to the objects it touches. By placing it upon one of the objects of the Springboard, this object starts to vibrate, and these vibrations are amplified by the contact microphone. This effect can be heard around 3’24” in the video above. Eric uses the tactile transducer as a kind of very special mallet or bow, being able to play his instrument in yet another way. In the next video Eric explains some of his playing techniques:

Eric is regularly performing with other musicians, and one of them is Birgit Ulher, who is using loudspeakers as a trumpet mute. In this video their performance as a duo starts at 40′:

Touche Nature by I-lly Cheng

We Spoke plays Touche Nature by I-lly Cheng
We Spoke plays Touche Nature by I-lly Cheng. © I-lly Cheng.

Vibrations of loudspeaker membranes cause air pressure waves, which our hearing system perceive as sound. As long as they are travelling through the air, these sound waves stay invisible to human beings. But as Ernst Chladni described in his book Entdeckungen über die Theorie des Klanges already in 1787, sound can be visualised by bowing a surface lightly covered with sand. So-called Chladni patterns are produced in this way. In her piece Touche Nature (2017) I-lly Cheng creates a phenomenon similar to Chladni patterns by placing transparent bowls filled with water on loudspeakers. The sound waves are visualised as water waves:

A bowl filled with water is placed upon a big loudspeaker in I-lly Cheng's piece Touche Nature
A bowl filled with water is placed upon a big loudspeaker in I-lly Cheng’s piece Touche Nature. © I-lly Cheng

A contact microphone is attached to the bowl and amplifies the bowl itself and the water movements in the bowl. Four percussionists each play a bowl filled with 1000 ml of water. During the performance the percussionists produce sounds by moving the water with their hands, rubbing the bowl, throwing stones in the bowl or pouring more water in the bowls. These sounds are all picked up by the contact microphones and then amplified  through the PA system. The water sound itself is also picked up by four condenser microphones and amplified directly through the loudspeakers in the hall.

The first page of the score of Touche Nature by I-lly Cheng.
The first page of the score of Touche Nature by I-lly Cheng (for the attentive reader: in the original version 500 ml water was used, but this was corrected to 1000 ml). © I-lly Cheng

As the first page of the score shows, the sound is processed with a pitch shift effect in the computer and there is also some feedback used. The feedback is created by sending the signal of the contact microphones back to the four loudspeakers underneath the bowls. There is no direct feedback happening though, but a pair of two loudspeakers and two microphones is together producing one big feedback loop.  The sound picked up by the contact microphone of player 1 is sent to the loudspeaker of player 3, which is then picked up by the contact microphone of player 3, creating a feedback loop by sending it to the loudspeaker of player 1. The same feedback is created between player 2 and 4.

An overview of the loudspeakers and contact microphones used in Touche Nature. The four condenser microphones used for direct amplification of the water sounds are not on the picture.
An overview of the loudspeakers and contact microphones used in Touche Nature. The four condenser microphones used for direct amplification of the water sounds are not on this picture. © I-lly Cheng

You can hear different kind of effects, including some feedback, at the very beginning of the piece, performed here by We Spoke:

During the piece I-lly explores the sonic world between natural water sounds and more abstract percussive rhythms. At the end of this fragment some pre-produced sounds are played through the loudspeakers, creating big movements in the water. These movements can not only be seen but the water sound caused by these movements is amplified through the condenser microphones. The loudspeakers seem to become liquid themselves:

Speaker Dress by Pauchi Sasaki

speaker dress Pauchi Sasaki
Pauchi Sasaki wears her Speaker Dress (2014), containing 96 loudspeakers. Photo by Juan Pablo Aragon. © Pauchi Sasaki

Our clothes can be seen as a form of communication between ourselves and the outside world. They give a visual impression of who we are and how we would like to be seen by others. Pauchi Sasaki designs dresses which are not only visible, but transmit sonic xterial as well. These dresses consists of around 100 loudspeakers, and are able to process sound live.

Pauchi got the idea for developing sonic costumes, when she performed in a temple in Lima. As she remembers: “But of course, it’s an ancient temple, so there was no electricity or outlets; I could perform only acoustic sounds, even though that’s not what I had planned. That’s when I got the idea of a self-contained system, but one that could be integrated into my body, that was the idea” (interview by Michael Barron).

The result was developed in 2014 and is simply called Speaker Dress. It is a self designed wearable sound sculpture. Two dresses exist nowadays, a black and a white one. The black one contains 96 loudspeakers, the white one even 125. Several loudspeakers are connected to the same amplifier channel. The black dress for example contains six channels of amplification, resulting in 16 loudspeakers per channel, and in six different sonic zones on the dress (a zone is formed by the loudspeakers diffusing the same sound).

Pauchi Sasaki Speaker Dress
Pauchi Sasaki in performance with her Speaker Dress. Photo by Janice Smith-Palliser. © Pauchi Sasaki

The performer can choose from different input possibilities: a contact microphone, a lavalier microphone and an mp3 player are connected. These signals are sent wireless to a computer, which processes the sound in the music software Max. The sound is sent back to the dress again and is diffused by the loudspeakers.

This is a short video made during a sound check for the Ojai Music Festival made by sound engineer Nick Tipp. Pauchi is testing the dress and walks through the auditorium:

All kind of live sounds made by the performers can be processed live during the concert and the transformed version is sounding through the dresses. Flutist Claire Chase and Pauchi herself, who is a violinist as well, use their breath, their voices and their instruments in the first composition Pauchi composed for  two dresses: Gama XV (2016). The performers are dressed in their own sounds, transformed by live electronics:

Apart by Oscar Bettison

tuning forks Rudolph Koenig Tonometer
A tonometer built by Rudolph Koenig in 1876. (source:

As I describe in Chapter 3 of Between Air and Electricity tuning forks are in some ways a kind of predecessors of microphones and loudspeakers. Furthermore they can be seen also as a predated sine tone generator. Tuning forks were extremely important for nineteenth century acoustic research. A tonometer, for example, was a large set of tuning forks and used to define the frequency of other sounds. The one depicted above was made by Rudolph Koenig and contains 670 tuning forks from 16 to 4096 Hertz. It was exhibited during the  Philadelphia Exposition of 1876 and apparently regarded as being “the most scientifically important instrument at the event”. (see Smithsonian National Museum of American History).

Eight of the 26 tuning forks used by Oscar Bettison in his composition Apart for amplified tuning forks. Picture by Matt Finch © Oscar Bettison

Nowadays tuning forks have left the scientific realm, and even for tuning often a digital device is preferred. But now and then they become part of a musical performance. Oscar Bettison uses two sets of tuning forks, each forming a chromatic scale from C4 (261.63 Hz) to C5 (523.25) in Apart (2012) for four percussionists. Each percussionists has six or seven differently pitched tuning forks. Oscar mentioned to me, that he is fascinated by tuning forks, because “For me they are like this beautifully dumb instrument—each one only has one note, but it’s a “perfect” note!”

One of the aspects which turns these tuning forks in Apart into a musical instrument—and which interests me in particular of course—is the use of amplification. The sound normally only heard privately in a singer’s head to find the right pitch, is made public in the concert hall now. Also, this amplification clearly influenced the compositional process, when Oscar worked with Sō Percussion to develop this piece: “In the studio we were thinking of resonant surfaces [to amplify the tuning forks], but nothing was particularly amazing, so we thought we’d try contact mics. The first problem was that tuning forks buzz, so we covered the mic enough to get rid of the buzz, but for it still to amplify. I’d already written material for them to play, it was a kind of chorale, but then we started using the amplification and we realised that the mic was a playing surface—they could strike the tuning forks somewhere else and then place them on the surface slowly or really quite rapidly.”

tuning fork contact microphone
For amplification of the tuning forks a contact microphone attached to a playing surface is used. This surface is covered with a heavy cloth, folded a few times, to damp the sound of the tuning fork touching the surface. © Oscar Bettison

A weird relationship between the visual and audible aspects of sound production is characteristically for Apart. The biggest gesture—a tuning fork being hit to bring it into vibration—is nearly silent, whereas the sound being heard is caused by the small gestures placing the tuning forks on the surface equipped with the contact microphone. Sonically, a weird organ sound is the result, often emphasised by two percussionists playing the same pitch. The tuning fork resonances are slowly getting softer and then interrupted by a soft click of the tuning fork being hit to vibrate it again. At the end of each section in the score (see the score fragment below), Oscar asks all percussionists “to strike the fork(s) they require for the next bar simultaneously” and this should be done “as a grand gesture”.

So Percussion performs Apart
Sō Percussion performs Apart. © Oscar Bettison
score Oscar Bettison Boosey & Hawkes
Three bars of the score of Apart by Oscar Bettison. The abbreviations R.P., I.P. and I.A. are all descriptions of rhythms for putting down the tuning forks on the cloth above the microphone, see also the explanation below. © copyright Boosey and Hawkes, Inc.
With kind permission of Boosey & Hawkes Bote & Bock, Berlin

The ways of placing the tuning forks on the cloth covering the contact microphone are notated precisely in the score and are the main feature of the piece. For example:

– R.P. is the abbreviation for Regular Pulsing and indicates to “chose a tempo and pulse the tuning fork(s) on the playing surface”.
– I.P. is the abbreviation Irregular Pulsing and one has to “Pulse the tuning fork(s) irregularly on the playing surface ending with a sustained note”.
– I.A. is the abbreviation for Irregular Alternation and the percussionist should “Alternate two tuning forks in a polyrhythm”(from the performance instructions of the score of Apart by Oscar Bettison, Boosey and Hawkes).

These different kinds of pulsations move slowly from the highest to the lowest tuning forks during the composition. The soft clunks of the unamplified tuning forks—sounding when hit to bring them into vibration—are a beautiful counterpoint to the airy sounds, produced when the forks are amplified. You can listen here to a recording of the piece, performed by Sō Percussion: