They missed the point. There’s no such thing as silence. What they thought was silence, because they didn’t know how to listen, was full of accidental sounds. You could hear the wind stirring outside during the first movement. During the second, raindrops began pattering the roof, and during the third the people themselves made all kinds of interesting sounds as they talked or walked out.

— John Cage speaking about the premiere of 4′33″

Kostelanetz 2003, p. 70
John Cage Graphic Score for 4’33”
https://www.pinterest.com/pin/177047829075554510/