How the Travel Sequence and Mortality Sequence Became On the Run and The Great Gig in the Sky

Before Dark Side of the Moon was a polished album, the band road-tested many ideas on tour in 1972. The “Travel Sequence” was a loose instrumental jam built around a driving bassline and guitar arpeggios, intended to evoke the anxiety of flying. It had no synth or tape effects yet—just the band playing live. Once in the studio, that section was completely reimagined: Roger Waters’ EMS VCS 3 synthesizer replaced the live instruments, and a tape loop of a running airplane engine gave it that frantic, claustrophobic feel. The result became “On the Run,” with none of the original Travel Sequence left except the core concept of travel as dread.

Similarly, the “Mortality Sequence” was a sparse organ piece (usually played by Rick Wright) over which a recording of a preacher reading from the Book of Common Prayer was layered. It was creepy but a bit blunt. During the album sessions, Waters wanted a more universal meditation on death. Alan Parsons suggested bringing in session singer Clare Torry, who improvised the wordless vocal overdub in one take—an emotional cry that replaced the spoken Bible passage entirely. What had been “Mortality Sequence” became “The Great Gig in the Sky,” one of the most powerful moments on the record. Neither early version survived the transition, but both left ghosts in the final tracks.