Steve Reich’s Pendulum Music is a classic feedback piece from the early days of minimalism and process music. Old pieces of the avant-garde can seem dusty, but feedback, which is unique in each instantiation, each resonant cavity in which it is found, should never actually get old. I wanted to add another wrinkle in the story of this piece, and so shifted the medium from sound to light. Instead of speakers, I use oscilloscopes, and instead of a microphone, I use homemade light microphones made from photodiodes. Besides this, the basic structure of the piece is unchanged.  Performers release the microphones from on high to start the pendulum, wait until the motion of the microphone stops, and then pull the power cord to end the piece.

The oscilloscopes operate in XY mode, which leaves some unresolved questions as what to do with the other axis in my transcription of this piece. In this version, each scope modulates each other scope, and the feedback pattern is inherently unstable. The visuals produced are a far cry from Lissajou patterns. One of the most satisfying results of this transcription was the silence photo-feedback provided me.  I was able to set up and tune the system without listening to it, and once I found the most interesting visuals, I turned on the amplifier to listen to the music it was making.

transcribed by Daniel Fishkin

performed by Daniel Fishkin and Ron Shalom
filmed and edited by Neo Sora
thanks to peter b for the blue scope!