the initial pressing of The Ultimate Collection contain a four-track bonus disc of rarities featuring the rare U.S. single version of "Substitute," an early version of "I'm a Boy," a previously unreleased acoustic version of "Happy Jack," and the U.K. single version of "Magic Bus." All are nice rarities, but collectors will have to consider if they really want to buy a double-disc set of everything they already have just to get four songs.