If he were alive, Cage would have celebrated his 100^th birthday last week. In this, his centenary year, as events are staged across the globe to celebrate his life and work, 4’33” has lost none of its radical edge. Describing 4’33” is fraught with difficulty. Cage wrote the piece in three movements totaling 4’33”. No instruments are played, if performed at a piano, as it often is, the lid of the piano is raised and lowered to indicate the end and start of each movement, the performer may have a stopwatch or timer (of course - how else to gauge 4 minutes 33 seconds), there are no musical notes, and yet, there is a musical score. It is not silent, though it is often referred to as such.