How Pink Floyd built the sound effects for The Dark Side of the Moon

The iconic heartbeat that opens and closes The Dark Side of the Moon wasn’t a real heart at all — it was a four-on-the-floor kick drum recorded through a limiter and then slowed down slightly to give it that thudding, organic pulse. Engineer Alan Parsons miced a microphone against a chest for the main heartbeat, but the final version mixed in the processed kick drum because it cut through the mix better.

Most of the album’s sonic weirdness came from the band dragging tape machines and microphones into everyday life. They recorded coins being thrown into a ceramic bowl at a restaurant for the cash register moments in “Money,” and for “On the Run” they fed a VCS 3 synthesizer’s output through a tape echo that David Gilmour manually sped up and slowed down. The “speaking clocks” on “Time” were literally recorded from a store-bought announcer’s clock, then each word was spliced onto separate tape loops so they could be triggered individually in the studio.

The spoken-word fragments that drift through the album were recorded in the studio lobby on a Nagra recorder — the band set up a microphone and asked random people questions about violence, death, and madness. They had no idea those answers would become the quasi-consciousness of the record. Parsons later said the biggest challenge was keeping all the tape loops synchronized without the machines eating the tape.