John Cage
«4'33''»

«The first performance of John Cage's 4'33" created a scandal. Written in 1952, it is Cage's most notorious composition, his so-called ‹silent piece›. The piece consists of four minutes and thirty-three seconds in which the performer plays nothing. At the premiere some listeners were unaware that they had heard anything at all. It was first performed by the young pianist David Tudor at Woodstock, New York, on August 29, 1952, for an audience supporting the Benefit Artists Welfare Fund – an audience that supported contemporary art.
Cage said, ‹People began whispering to one another, and some people began to walk out. They didn't laugh -- they were just irritated when they realized nothing was going to happen, and they haven't fogotten it 30 years later: they're still angry.›
To Cage, silence had to be redefined if the concept was to remain viable. He recognized that there was no objective dichotomy between sound and silence, but only between the intent of hearing and that of diverting one's attention to sounds. "The essential meaning of silence is the giving up of intention," he said. 7 This idea marks the most important turning point in his compositional philosophy. He redefined silence as simply the absence of intended sounds, or the turning off of our awareness.»3

(source: Cage conversation with Michael John White (1982), in Kostelanetz 1988, 66, in: Solomon, Larry J.: The Sounds of Silence, in: http://www.azstarnet.com/~solo/4min33se.htm)