Another way of working is setting deliberate constraints that aren't musical ones - like saying, "Well, this piece is going to be three minutes and nineteen seconds long and it's going to have changes here, here and here, and there's going to be a convolution of events here, and there's going to be a very fast rhythm here with a very slow moving part over the top of it." Those are the sort of visual ideas that I can draw out on graph paper. I've done a lot of film music this way.

It's nice, I think, when people use your music for things you didn't think of.

The problem with improvisation is, of course, that everyone just slips into their comfort zone and does sort of the easy thing to do, the most obvious thing to do with your instrument.

You know that in order to copyright material somebody has to write it down for you. Any piece of recorded material has to be scored in order for it to be copyrighted. I've seen the scores of my things and they don't resemble the music in any way. If you give them to somebody who has never heard the music and say, "What does this sound like to you?" they'll play you something that has no relationship with the music it derives from. Notation simply isn't adequate.

With devices my technique is always to hide the handbook in the drawer until I've played with it for a while. The handbook always tells you what it does, and you can be quite sure that if it's a complex device it can do at least fifteen other things that weren't predicted in the handbook, or that they didn't consider desirable. It's normally those other things that interest me.

I hate the thought that someone had picked up one of my song records and was really excited about it, and walks [out of] a record shop with On Land and is disappointed because it isn't what they wanted. So, I try to make signs, graphically and visually, to say to people "Okay, this is this department of my work and this is this other department of my work." And of course I'm very pleased if people like all of them, but I don't want them to feel deceived at any point.

I'm actually an evangelical atheist, but there is something I recognise about religion: that it gives people a chance to surrender.