4′33″ is a three-movement composition by American experimental composer John Cage. It was composed in 1952, for any instrument or combination of instruments, and the score instructs the performer not to play their instrument during the entire duration of the piece throughout the three movements.
John Cage talks about the meaning of inner sound.
He explains that sound is everywhere.
Listen to the following NPR story about John Cage.
Read the following NPR article about John Cage. Silence And Sound: Five Ways Of Understanding John Cage