The Theremin
Using the instrument as a proprioceptive sensor to control 3D modelling software and other digital representations of space.
Updates Feb 24
How it works
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I run the analog output from the theremin through an Analog-to-Digital Converter (ADC) to convert the audio output into digital audio, which my computer can read.
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Using the SoundDevice and librosa Python modules, I take the audio and group the data into larger matrices of information called blocks and break the input into numerical values of pitch, volume, tempo, etc.
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I pass these values along to Rhinoceros3D, a 3D modelling program, to generate and control 3-dimensional objects.
Background
In 2022, I was reading the Oliver Sachs' book Seeing Voices, which is a series of essays on the world of the deaf. In it, he described sign language as language that was communicated in space.
By this, I think he simply meant that the gestural qualities of American Sign Language grant the signers the ability to communicate nuances that those who don't sign might have trouble imagining.
However, I was taken by the idea that the fundamental elements of our lives (space, language, time, etc.) could be merged to create different experiences. In particular, I became interested in the idea of somehow experiencing and playing music through space.
I designed and built the case out of Pin Oak, milled from trees taken out of the East River Park
I chose to use a theremin because unlike virtually every other instrument, it lacks any haptic feedback. Whereas a guitarist might feel their finger on a fret, or a trumpeter knows what note will play based on how their lips are shaped, the theremin requires the musician to know where their body is in relation to the instrument.
With the exception of a few modifications for my case, I built the circuitry off of the Paia Theremax design.
Plans for the Future
Now that we have a simple means of controlling space, how do we translate the nuances and complexities of live performance?
Velocity
Think of velocity in the way of a piano player pressing a key. If the player presses it gently, it is being played with less velocity, and vice versa. But velocity isn’t just loudness - different tones are produced at different velocities.
The schematic section marked with pink is the theremin’s version of velocity, and produces distortions in the circuit’s frequency when rapid changes in volume are detected. I can use the onset of those distortions to trigger an event in my script.