I've just finished reading this intriguing and infuriating book; an analysis of and discussion about the meaning of John Cage's 4'33".

Although 4'33" has been widely accepted as some sort of joke or satire, author Gann makes a strong case for it being as valid a musical work as any other of Cage's oeuvre. He has played the piece in many concerts and has, evidently, made a great study of what he believes to be the meaning of the piece.

Cage's aim was to prove that by "putting a frame around silence", it becomes as rewarding as any other form of music. It seems he made a study of what is meant by silence, even spending time in an anechoic chamber (although I'm not altogether convinced that he could hear the sound of his own nervous system whilst in there)

He produced several versions of the manuscript score with varying levels of instructions to the player but all, of course, ensured that the audience was concentrating on listening to the environment in which the piece was performed.

Personally, I think Cage did a wonderful thing - reminding people that even (supposed) silence has a sound - but I remain to be convinced that dressing it up as a 'proper' musical piece with all the trappings of a score, playing instructions and the like was anything more than window-dressing which, in itself, starts to turn the piece into the joke it is so often believed to be.

http://www.amazon.co.uk/No-Such-Thing-Silence-America/dp/0300136994/ref=... (other online bookstores are available)