When EMI and Capitol released the Beatles' recordings on compact disc, it was decided to issue the albums in their original British formats in both the U.K. and the U.S. The British albums frequently did not contain singles released by the Beatles at the same time, and there were other odd tracks not included on any regular album. Thus, two discs were necessary to gather the stray material (some of which included their biggest hits). For the cassette and LP formats, Capitol combined the two volumes into this double release. ~ William Ruhlmann, All Music Guide