And then John Cage! I read a bio of Cage several years back, and while I don't love everything in his work, he was an interesting Zen presence in the world of music. The Fluxus, conceptual aspect of Cage is intriguing and inspiring. I performed in a theater piece in college where I used some of his ideas for creating using random selection to inspire musical structure.
Here, Cage says:
Is it a sound? If so, is it music? Is music the word I mean? Is that a sound? If it is, is music "music"?
In the film, Cage addresses his famous piece 4:33 as non-obtusely as I've ever heard him:
Silence is not a question of a little sound or more sound. There's no such thing as no sound. It's just a question of what sounds we intend, and what sounds we don't intend.