Though released as a double-disc CD in the United Kingdom and in the rest of Europe, the original CD release in the United States was only one disc, with three tracks (“Quatrain”, “Sweet Dream” and “Conundrum”) omitted to fit the 80 minutes CD length, while the double-disc 1990 CD version in the United Kingdom (and Europe) incorporated the first track for both discs (the Introductions) in the song that follows.

In 2004, the complete album was released worldwide as a two-disc set with the Introductions as separate tracks.