 The album is essentially a scaled-down version of the four-CD "Led Zeppelin Boxed Set".This compilation set came about as a result of the initially rushed conversion of Led Zeppelin's album to the compact disc format in the late 1980s.Led Zeppelin were among the first rock bands to be re-issued on CD, but such was the haste to capitalise on the new format that the new CDs were derived not from re-equalised master tapes, but from sound-generation tapes that had been equalised for the original vinyl platters.