From the Wikipedia lemma:

4′33″ (pronounced “four minutes, thirty-three seconds” or just “four thirty-three”) is a three-movement composition by American experimental composer John Cage (1912–1992). It was composed in 1952, for any instrument or combination of instruments, and the score instructs the performer(s) not to play their instrument(s) during the entire duration of the piece throughout the three movements. The piece consists of the sounds of the environment that the listeners hear while it is performed […].

I love this. It’s just such an appreciation that the audience should not be considered a nuisance to the creator, but always a vital part of it. Any separation of the two would be an illusion.


This great anecdote:

In 1951, Cage visited the anechoic chamber at Harvard University. An anechoic chamber is a room designed in such a way that the walls, ceiling and floor absorb all sounds made in the room, rather than reflecting them as echoes. Such a chamber is also externally sound-proofed. Cage entered the chamber expecting to hear silence, but he wrote later, “I heard two sounds, one high and one low. When I described them to the engineer in charge, he informed me that the high one was my nervous system in operation, the low one my blood in circulation.”