[Improvisation ] is been with me all my life. We all do it.

[Students] they did the sonic meditations, I would observe them in their ensembles, and the ensembles improved incredibly. So I knew I had something to do and something to say.

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.

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

Listening is selecting and interpreting and acting and making decisions.

One day I decided I would like to put a record into my system. So I picked up a record that was lying on the table, and put it on. I didn't bother to look at what it was because I didn't care, and it turned out to be Madame Butterfly. So I processed the aria from Madame Butterfly in my system and I played with it.

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.