How Pink Floyd Built a Sonic World: Recording the Heartbeat, Clocks, and Cash Registers for The Dark Side of the Moon

Most people know The Dark Side of the Moon for its swirling synths and existential lyrics, but the album’s soul is buried in its sound effects. The heartbeat that opens and closes the record isn’t a synthesizer—it’s the real thing. Producer Alan Parsons recorded his own heartbeat, then slowed it down to create that deep, ominous thump. He sat in the control room with a microphone pressed to his chest while engineer Peter James ran the tape at a slower speed. The final sound is still Parsons’ heart, just speaking in a lower register.

The ticking clocks were captured in a different way. Rather than recording one clock, the band went to an antique clock shop in London and recorded a whole roomful of them—grandfather clocks, wall clocks, wristwatches, all ticking at once. The mixers then layered and edited those sounds to create the chaotic, overlapping timepiece collage in “Time.” For the cash registers in “Money,” engineer Chris Thomas spent an afternoon at a hardware store buying a cheap cash register, then recorded it rattling through coin slots and drawer slams. They slowed that tape down and looped it into the iconic 7/4 time signature, turning everyday noise into one of rock’s most recognizable intros.