Apart by Oscar Bettison

tuning forks Rudolph Koenig Tonometer
A tonometer built by Rudolph Koenig in 1876. (source: www.americanhistory.si.edu/science/tuningfork.htm)

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:

Sound in a Jar by Ronald Boersen

speaker jar microphones
Different microphones are used to pick up the sound from the small loudspeaker in the jar. © Ronald Boersen

In Sound in a Jar (2016) by Ronald Boersen three performers— Ronald Boersen himself, Dganit Elyakim and Hadas Pe’ery—move three different microphones back and forwards to a very small loudspeaker placed in a jar. As Ronald explained me, this piece is a sound environment, which changes and developes algorithmically during the performance. The main task for the performers during the rehearsals is to explore this environment and find ways to engage musically with the sounds they can produce. The performers pick up the sounds of the loudspeaker in the small jar and it is sent back to the loudspeaker again, passing through a Max patch. By placing the loudspeaker in a jar, the sound will resonate easier, a very suitable feature for acoustic feedback. The main sound of the performance is thus acoustic feedback, coloured by the different characteristics of the three microphones used (two different condenser and a dynamic microphone).

microphones loudspeakers max msp
This scheme gives an overview of the inputs and outputs of the piece, as well as the three forms of live processing used, in form of a Max patch. © Ronald Boersen

The Max patch processes this feedback sound: as the scheme depicts, Ronald uses threshold triggered reverb pulses, feedback interval driven harmonisation and granular delay lines. By using amplitude thresholds and feedback frequencies these processes are directly influenced by the feedback sound itself, and the feedback itself is processed by the Max patch. In this manner Sound in a Jar uses a double form of feedback: acoustic feedback (using the sound itself) and data feedback (by using data streams generated from amplitude and frequency analyses of the loudspeaker sound, without using the sound itself), and both are effecting each other constantly. How much the sound of each microphone is processed by Max and which of the three processes is used (reverb pulses, harmonisation or granular delay) is changing during the piece, as is depicted in the diagram in the score. The relationships between microphone, processing and loudspeaker change not only accordingly to the distance between microphone and loudspeaker but also because of the temporal development of the kind of sound processing in the Max patch.

In this close-up video the development in sound processing and the direct relationship between the movements of the microphones and the resulting sound can easily be followed:

A very appealing aspect of this set-up is in my view, is that all three microphone signals are connected to a single loudspeaker. All three players have to find their own way of playing, because they have a different type of microphone and their sound is processed in a different way, but at the same time all these different paths come together again in a small loudspeaker in a jar. In the second part of the performance the sound of the small loudspeaker is slowly also diffused through the bigger loudspeakers in the hall (the PA loudspeakers). This does not cause any noticeable change in the acoustic feedback interaction, but the spatial and spectral characteristics do change due to the different in placement, sound diffusion and spectral response of these loudspeakers. The sound of the jar itself seems to fill the whole performance space now, instead of occupying a single spot. At the end of the piece, the loudspeakers in the hall fade out again and the sound moves back into the jar.

By preparing this text I also discovered that Ronald Boersen has an interactive sound installation, that uses loudspeakers and ping pong balls. I added this to the collection of fifty years of loudspeakers and ping pong balls.

And here a recording of the whole piece:


Transducer by Robin Fox and Eugene Ughetti

microphone swinging loudspeakers
Eugene Ughetti swings a microphone above his head, whilst three other Speak Percussion members are holding loudspeakers. Video still © Robin Fox & Eugene Ughetti

In Transducer (2013) you might easily recognise all kinds of “classical” playing techniques for microphones and loudspeakers, twisted in surprising and clever ways. This results in a performance which reinvents and expands known pieces such as Steve Reich’s Pendulum Music, Karlheinz Stockhausen’s Mikrophonie I or Gordon Monahan’s Speaker Swinging into unexplored territories. Robin Fox and Eugene Ughetti composed this piece for Speak Percussion (Eugene Ughetti, Matthias Schack-Arnott and Leah Scholes, and guest percussionist Louise Devenish are on stage).

As the title Transducer already implies, this piece is focusing on so-called  transducers: devices that transform one form of energy to another, a category microphones and loudspeakers belong to. The piece starts with a scene which reminds me of the swinging loudspeakers in Gordon Monahan’s Speaker SwingingBut this time a microphone circulates above Eugene’s head, and is, for example, picking up sounds diffused by loudspeakers carried around by  other performers:

One of the main elements on stage is an array of eight microphones hanging above eight small loudspeakers, which remembers us of Steve Reich’s Pendulum Music. Although clearly inspired from the swinging microphones used by Steve Reich, this pendulum-array—containing more and smaller pendulumsis played in a different way, or more accurately: in many different ways. Reich’s Pendulum Music is process-based and acoustic feedback is its sole sound. After releasing the microphones the performers do not interfere anymore with the swinging microphones. The performance is finished as soon as the microphones are hanging stationary above the loudspeakers.

Pendulum Music, Transducer
Eight pendulums of microphones and loudspeakers are played in many different ways during Transducer. Video still © Robin Fox & Eugene Ughetti

In Transducer Robin and Eugene develop an instrumental set-up with the pendulums, which produce many different sounds such as clicks, sine waves or noise. These different type of sounds are generated with the help of patches programmed in the software Max. The pendulums in Transducer also do not feedback acoustically, but the swinging microphones amplify the sound coming from the loudspeakers underneath them in pulses: the closer the microphone moves to the loudspeaker the louder the sound gets. The signals of the microphones can be amplified through eight bigger loudspeakers placed around the audience.

audience PA
Eight loudspeakers and two subwoofers are placed around the audience during Transducer. (Many other loudspeakers and microphones are placed on stage, see the schedule below for their placement). © Robin Fox & Eugene Ughetti
circuit overview Transducer
This is an overview of all equipment involved during Transducer. (Only the  eight channel loudspeakers placed around the audience are not on this scheme). © Robin Fox & Eugene Ughetti

The whole set-up for Transducer contains many different kinds of microphones and loudspeakers, and therefore a huge amount of possibilities for combining these. Besides the elements mentioned earlier, there are four different tables, all focusing on a specific topic of playing microphones and loudspeakers. On the Textured Table different surfaces are triggering a contact microphone to obtain musical material and have it feeding back through other loudspeakers and microphones. On the Speaker Table a loudspeaker is placed, which membrane moves other objects (including some ping pong balls!), and in fact is acting as a percussionist. The third table is the so-called Mic on Mic table, on which a microphone is amplifying another microphone, which itself is not amplified. The Electromagnetic Table creates sounds with the use of an induction coil and a pulled-open computer.

contact microphone surface
The Textured Table: using  a contact microphone for amplifying several kinds of surfaces. Video still © Robin Fox & Eugene Ughetti
two microphones amplification
The Mic on Mic Table: a microphone is amplifying another microphone, which itself is not amplified. Video still © Robin Fox & Eugene Ughetti

The piece ends with acoustic feedback: Eugene Ughetti approaches two loudspeakers with a microphone. In between them a big tam-tam is placed and starts to resonate according to the frequencies diffused by the loudspeakers placed right behind it. The acoustic feedback is coloured by the resonances of the tam-tam and by moving the microphone close to the tam-tam changes in resonances can be picked up. This might remind you of another well-known composition for microphones as musical instruments. And indeed, the second part of this Speak Percussion concert continues with Mikrophonie I by Karlheinz Stockhausen.

acoustic feedback tam-tam
In this acoustic feedback set-up a tam-tam is placed between microphone and loudspeakers. Video still © Robin Fox & Eugene Ughetti

The whole documentation video of Transducer can be viewed here:

Fifty years of loudspeakers and ping pong balls

Some objects seem particularly suitable to be used for preparing loudspeakers. The lightness and characteristic sound of ping pong balls might be a reason, why they have been favourable objects for this. Comparing several of these set-ups reveals that—fortunately!—using a similar technology can still result in completely different works.

Loudspeakers ping pong balls
Leser 1 by Manfred Mohr and Jochen Gerz. The loudspeakers and ping pong balls are covered by a large transparent plastic bag. Polyester tube, 19 loudspeakers,  printed transparent plastic bag, 19 moving ping pong balls, electric motor, 180 cm x 45 cm, 1967 Source: www.emohr.com/collab-exp/col_mohr-gerz.html © Manfred Mohr and Jochen Herz

As far as I know, the first work using ping pong balls in combination with loudspeakers is Leser 1 (1967) by Manfred Mohr, who created the audio sculpture, and Jochen Gerz, who wrote the text for this installation. This  tower contains 19 loudspeakers, each prepared with a single ping pong ball and was exhibited for the first time in 1968 in Paris. The audience can press a foot pedal to turn the installation on for a minute. Three different frequencies are then played through the loudspeakers and causing the ping pong balls to move away from the loudspeaker membranes and hit the plastic bag (see also the scheme at the end of this post). The ping pong balls are alternating between striking the plastic bag and the loudspeaker membrane and the combination of 19 ping pong balls making this movement produces a noisy sound. Together with the text printed on the big plastic bag and a random letter printed on each ping pong ball the whole installation seems to make an attempt to speak. The text itself seems also to be related to the movement of the ping pong balls: the big letters in the middle read: “Auf Flüchtlinge wird [ge]schossen”, which could be translated as “shoot the people fleeing”. Manfred Mohr explained me, that this text refers to the fact that at that time the East German police had the order to shoot the people fleeing to West Germany.

In Music for Pure Waves, Bass Drums and Acoustic Pendulums (1980) Alvin Lucier uses four bass drums and places them in front of four loudspeakers. A low sinus sweep is played through these loudspeakers and the membranes of the bass drums start to vibrate, according to their resonance to the frequency of the sinus wave. In front of each drum a ping pong ball is hanging from the ceiling, just touching the drum head. The vibrations of the skin push the ping pong ball away from the drum. Depending of the moment of hitting the drum, when the ball falls back, as well as the direction and amount of vibrations of the drum head, the ping pong ball will be pushed away next time with more or less force. Although the set-up seems to be four times the same, the results of the small differences in material of bass drum, loudspeaker and ping pong ball can be clearly perceived in the movement of the ping pong balls and the resulting sound. The shape of the ping pong balls reminds me of the head of a drum stick, and these drums seem mysteriously “played” by the ping pong balls.

Christian Skjødt uses 16 loudspeakers and an equal amount of ping pong balls in Inclinations (2016). Here again each loudspeaker with ping pong ball combination creates its own rhythm, but due to the ping pong balls moving in upwards direction they fall down much faster than in Lucier’s set-up. This causes a constantly changing, soft and noisy rumbling. Christian is not using any other material such as a plastic bag or drums. Since the frequencies played through the loudspeakers are too low for humans to be heard, all sound is produced by the collisions of ping pong balls and loudspeaker membranes. The minimal visual quality of this installation underlines the focus on these sonic events.

loudspeakers ping pong balls
The three different relationships between ping pong balls and loudspeakers, from left to right: In Leser 1 the ping pong ball hits the loudspeaker and the transparent plastic bag. In Music for Music for Pure Waves, Bass Drums and Acoustic Pendulums the loudspeaker just hits the drums. In Inclinations the ping pong ball is placed directly on the loudspeaker.

After I finished this post on loudspeakers and ping pong balls, Ricardo Arias brought the piece PingRoll (1997) by Manuel Rocha Iturbide to my attention:

And João Ricardo mentioned Kugel-Percussion (2006) by Peter Vogel to me:

loudspeaker ping pong ball
Kugel-Percussion by Peter Vogel, with one ping pong ball and one loudspeaker © Peter Vogel

And another addition: When preparing my text on Sound in a Jar I bumped into another piece of Ronald Boersen, using loudspeakers and ping pong balls, called talk to me… . The ping pong balls are hanging in front of a tam-tam . You talk into a microphone and see and hear your speech reflected in the movement of the ping pong balls. To achieve this, the voice is processed in the computer, attenuating resonating quality in the speech, that maximises the response of the resonating frequencies of the tam-tam. This sound is than diffused through a tactile transducer attached to the tam-tam. The ping pong balls start to move due to the tam-tam vibrations, creating sounds themselves as soon as they hit the tam-tam: