I noticed you could monitor the recording that you're making, but you could also monitor the playback head. There's a little distance between them and so you get an echo, right? If you change the amplitude of, say, the playback and play with that, you get different qualities and different sounds. So I was very interested in that phenomenon.

Maybe I'll start from the initial idea, what motivated me to do that. In 1953, I had access to a tape recorder. Tape recorders were not widely available. There was no cassette tape back then. It was a Sears Roebuck tape machine. I put a microphone in the window and recorded the ambience.

I had invented my own system, my own way of making electronic music at the San Francisco Tape Music Centre, and I was using what is now referred to as a classical electronic music studio, consisting of tube oscillators and patch bays. There were no mixers or synthesizers. So I managed to figure out how to make the oscillators sing. I used a tape delay system using two tape recorders and stringing the tape between the two tape machines and being able to configure the tracks coming back in different ways.

Everybody improvises their way through every day. And so I do that with music.

In the beginning we were making tape music, meaning, we were making music on tape.

It might be fun to have audience members wander up the ramps as well, so they can listen from different vantage points.

When we had the San Francisco Tape Music Center, we had a couple of Ampex tape machines there, and I could string tape from one machine, past the heads, and over to the next machine to the supply-reel amp, and have another delay there.