Today in class we briefly mentioned John Cage's famous composition titled 4'33" - a work for solo piano that is "in three movements" but contains nothing but silence.
While there's a lot of humor (and chutzpah) in this composition, it's also thought-provoking. It gets to the question of the ontology (or "being") of music...the old question "What is music?"
Cage was a devotee of Zen meditation and ideas, and his contention was that 4'33" was not "silence" at all, even though there were no composed notes or sounds of any kind. So, where was the "music?"