"I shouldn't be surprised if the music of the future were in unison. Or is that only because I cannot clearly imagine several voices? Anyway I can't imagine that the old large forms (string quartet, symphony, oratorio etc.) will be able to play any role at all. If something comes it will have to be---I think---simple, transparent.
In a certain sense, naked.
Or will that hold only for a certain race, only for one kind of music(?)"
John Coltrane, Interstellar Space (1967):