Although the contract between The Beatles (Apple Corp.) and Cirque du Soleil stipulated only the Beatles' original music would be used in the show - and therefore it would be the first Cirque du Soleil production ever to forgo a live band and depend strictly on recorded musical backing - the show was able to use everything from the Beatles' recording vaults, including alternate versions, demos, and out-takes, as well as mixing and matching various individual tracks, so that, for example, musical director Giles Martin mashed up Ringo's stuttering drum track from "Tomorrow Never Knows" with Harrison's "Within You Without You," and combined "Lady Madonna" with "Hey, Bulldog."
At least one new bit of music was added, however, under the direction of original Beatles producer George Martin. The production chose to use a recording of George Harrison singing his "While My Guitar Gently Weeps" alone with acoustic guitar, rather than the well-known White Album version with the band and Eric Clapton doing the electric guitar solo; but Martin recorded a new arrangement of strings at AIR Studios in London to back the Harrison acoustic rendition. Part of that recording session is shown in this film.
The film notes that staging with the performers began in Montreal a full 300 days before the premiere, and the first dress rehearsal was 49 days prior.