David Tudor's 1960s/70s feedback loop pieces were created using chains of analog devices that manipulated gain, phase and EQ, with no external sound input. All sounds were created internally to the circuits, by feeding the output of the chain back to the input. This was an idea popularized in the 1990s by the "no-input mixer" genre of sound art / noise music production, which has spawned a couple of truly virtuosic performers.

In 1995, at the same time as I was visiting Tudor and assisting with organizing parts of his archive for eventual deposit with the Getty Research Institute, I bought a wonderfully programmable digital multi-effects box made by Digitech, and created some emulations of the types of feedback circuits Tudor used. Controlling the circuit using a bank of 16 MIDI faders made a very useful performance instrument, which I still bring out from time to time.

This piece, in its original version, layers a realtime improvisational performance with manipulation of three prerecorded improvisations, for a multichannel live concert piece that is an hommage to and study of Tudor's soundworlds. This remix is a more deliberately "composed" arrangement of excerpts from previous concert recordings. The interesting spatial movement is lost in this 2-channel mix, and a live layer I played over top is not present, but it gives the idea.

Photo on this page is a detail from a production still of Tudor working on his piece "Bandoneon !" for the 9 Evenings: Theatre and Engineering in 1966.