"With 'Revolution 9,' the Beatles said, 'We're about to do a sort of collage or montage of a few things.' They went up to the library at EMI and found loads of old tapes. They just nicked anything, like Cliff Bennett and the Rebel Rousers, Oxford and Cambridge music tests for A levels. Loads of things. They took everything down there and made copies of the bits they wanted. Sometimes they played them backward. Sometimes they chopped a little bit out. They literally did anything they liked with the bits of tape. Then they assembled some really good-sounding loops. One of the ones they 'bunged' on was this Oxford music exam. A guy was playing the piano and said, 'Number 9,' then he played another bit. Obviously you had to identify the bits that you knew. That's where 'Number 9' came from, and there's no significance in it."