For a number of years the central focus of my work has been on using the laptop, in combination with microphones, speakers, mixers, etc, as a performance instrument capable of sharing the stage with groups ranging from new music ensembles to world-class instrumental improvisers. I have done this by creating and coding software interfaces that create unique interactions with instruments and sonic spaces.
Both of the pieces below involve a piece of real-time software that I have coded to control feedback, and thus use feedback as a compositional tool. On paper this is a simple system. To get feedback, some output of the sonic environment is fed back into the system as input. This input is then output again and thus is part of the input again, etc, etc. In most cases the result is the undesirable sound of the microphone being too hot or too close to the speaker and exploding into one ear-piercingly intense tone that forces us all to cover our ears.
The single tone aspect of a feedback environment is important. This happens because the sonic energy of a signal gets built up around a specific frequency until that frequency dominates the sound. Once this pitch takes over the spectrum, there is no chance for any other pitch to take over, because all of the sonic energy in the signal is focused in one place.
However, as shown in Alvin Lucier’s classic work I am sitting in a room, sonic spaces reinforce many pitches, not just one. Essentially, the room is a filter that reinforces certain tones, causing them to be resonant, and weakens other tones, diminishing their audibility. In most feedback situations, the tone we hear resonating is likely the pitch most reinforced by the room (possibly altered by other factors, like where the microphone is in relation to the speaker).
However, because there are many pitches in any space, if one were to remove the most prominent feedback pitch from the space, a second pitch would rise up to take its place. If one were to remove that pitch, a third pitch would emerge. What my software does is allow, and in fact encourage, feedback to happen. At the same time, it listens to the sonic space and tries to detect if any single pitch has been feeding back for an extended period of time. If it has been, the software uses an fft filter to completely block that pitch. Because of the resonant quality of sonic spaces, a new pitch will then rise up and begin feeding back. The cycle can repeat forever, resulting in a beautiful cascade of tones that resonate with the room they inhabit.
What I realized in working on these two compositions is that the “filter” part of the feedback system, which is usually a room, could be anything in the circuit between the microphone and the speaker. In American Idols, the filter of the room is replaced by four electric guitars. These four guitars are each facing an amplifier, and thus causing the feedback situation. The sound leaves the speaker, vibrates the strings on the guitars, the vibration of which in turn goes out the speaker. The guitars will not feed back at any pitch. Rather, they only resonate at pitches that are found on the open strings – ie, the harmonic series of each guitar string. Therefore, in American Idols, the guitars are tuned to pitches which are part of one harmonic series, more specifically the series of 60hz, which is the series that guitar amplifiers will buzz at when plugged in and turned on.
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The guitars are arranged in a square around the installation space; one behind the televisions, one on the opposite wall, and two on either side. This creates an all encompassing surround effect that engulfs the audience and fills the space with sound. In addition to the sonic element in this piece, there are 12 televisions at the front of the exhibit. I send the four audio signals from the guitars directly into the televisions, causing them to display an image which corresponds nicely to the beautiful microtonal drone simultaneously occurring in the space.
Broken Symmetries (or the Masses of Gauge Bosons)
Broken Symmetries is a kind of installation/concert work, which creates a sonic environment for the audience to live in. This piece also uses my feedback control software as its foundation. This time, instead of guitars, however, I use a bank of resonating filters tuned to the harmonic series of the open strings on a violin. Because the sound travels out of the speaker and into the space (before it is picked up by the microphone), the room acts as an additional filter. I was originally going to use guitars, but the guitar feedback only works at high volume levels, and I wanted to have more dynamic control during this performance.
As seen in video, the speakers for feedback are set up behind the performing ensemble. The feedback presents a backdrop for the group, which layers over the top with cascades of sound. The piece begins with a substantial microtonal violin solo, performed beautifully here by Joshua Modney. The feedback begins about half way through the violin solo and the ensemble enters about seven minutes in. The following performance features the Wet Ink Ensemble – Joshua Modney (violin), Erin Lesser (flute), Alex Mincek (tenor saxophone), Eric Wubbels (piano), Ian Antonio (percussion), and Sam Pluta (electronics).
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This is part of a series of musician essays collected by Joseph Di Ponio.
Sam Pluta is a New York City-based composer, improviser, and sound artist. Known internationally for his laptop performances with groups like Rocket Science, Wet Ink Ensemble, and The Peter Evans Quintet, he is widely regarded as one of the most compelling electronics performers of his generation. He has performed as a laptop soloist and chamber musician at the Lucerne Festival, the Donaueschingen Festival, the Moers Festival, Bimhaus, Porgy and Bess, and the Vortex, amongst other international concert venues and festivals. As a composer, he has been commissioned and premiered by Mivos Quartet, Yarn/Wire, ICE, Timetable Percussion, RIOT Trio, So Percussion, Dave Eggar, and Prism Saxophone Quartet. He is Technical Director for Wet Ink Ensemble, a new music group dedicated to promoting music by young composers. A devoted pedagogue, he directs the Electronic Music Studio at Manhattan School of Music, teaches at the Computer Music Center at Columbia University, and is Academic Dean and Director of Electronic Music at the Walden School, a summer music program for young creative musicians. Sam’s music is released on quiet design and Carrier Records, a record label he runs with Jeff Snyder and David Franzson, and his performances can also be found on More Is More, Tzadik, and hat[now]ART. Sam holds a Doctorate in Music Composition from Columbia University and additional degrees from UT Austin, the University of Birmingham (UK), and Santa Clara University.