The first two compilations had already covered material released exclusively up to 1977 and Original Masters rehashes much of their material. However, Original Masters has different takes or mixes of some songs than those commonly heard. The reason is that many of the selections are early promotional versions that were sent to radio stations. The version of "Aqualung" included here has an entirely different recording of the middle acoustic section, which is allegedly the same used on the Quad release of "Aqualung" in the 1970s.
The CD's back insert, as well as the back cover of the LP's sleeve, mislabels the song "Witch's Promise" as "Witches Promise".