Actually, the score for 4'33" is probably one of the shortest scores ever written, easily fitting onto one page. This is the score:
I TACET
II TACET
III TACET
That's it, that's the whole thing. There's no instrument specified, and there are no instructions to the performer other than the total time of the piece. The first public performance used a piano, so it's come to be known as a piece for piano despite the openness of the score. The performer opened and closed the keyboard cover on the piano to mark the beginning and end of each movement, which was the only noise made by the piano.
-- Matthew Snyder Philadelphia, PA