closer to the noise
Morton Feldman and Iannis Xenakis In conversation
(for full text click the title above)

Morton Feldman and Iannis Xenakis, 1986
excerpt:
[…]
Xenakis: There are three reasons why I use quarter-tones.
The first reason is to enrich the sound with the beats that they produce and with the impossibility to distinguish pitches when they are very close, especially when you have many string instruments because they are able to vary the pitch in very small differences.
Another reason concerns the problem of scales. The scale is a fundamental thing that most of the contemporary musicians don’t consider. They take it for granted but in the past and in other cultures like Asia and Africa the scales are very differentiated. When you have chosen your scale it’s like producing your style already. For instance an octavating scale means from some point of view repetition: what you do in one range is the same thing in a lower range. You could enrich this by making a completely different, non-octavating scale.
I’ve observed that if you transcribe the music of China, Japan or India it immediately looks like western music. Western notation is an inaccurate notation, there’s a loss of information due to very small differences in the tuning of the scales. So I tried to produce a kind of theory that would be able to produce any kind of scale.
The third reason that I might use, not only quarter-tones but also differences in pitch, sometimes up to the comma, is that they might produce a sound more alive. lf you listen to the music from Java, you will hear that it is tuned in such a way that it looks false to our ears. Why? Because they want that. It’s not by chance, it’s because they feel that the unison shouldn’t be there at all. This kind of discrepancies are very alive. They think there’s no need to have absolute unisons or to have a regulated scate like we have in the West, which not only is a theoretical trend, but also has very practical reasons: when you have many instruments playing together, you need some identity. These conflicts are general and deep problems of music and we have the same problems with rhythm and intensities.
Feldman: But you noticed the score of the trio and the string writing where I don’t use quarter-tones but I use different spellings. For instance, I might have an octave out of tune, like an E flat and a D sharp. The reason I do this—I’m ashamed to tell you, but I’ve got a very good piano and I purposely keep it out of tune—is because it is warmer. I also use it tor the same reason that Mr. Xenakis mentioned, to differentiate within small intervals to get more clarity, say in a cluster. I think of it as. . . I use the word “turpentine”, it’s like thinning out the music with turpentine.
Xenakis: To get closer to a more complex sound — Feldman: Yes.
Xenakis: closer to the noise.
[…]
Wherever we are, what we hear is mostly noise. When we ignore it,
it disturbs us. When we listen to it, we find it fascinating.
The sound of a truck at fifty miles per hour. Static between the stations. Rain.
We want to capture and control these sounds,
to use them not as sound effects but as musical instruments.
John Cage (1967)