Welcome to the Machine

Originally titled The Machine Song, it was written by Waters and built from a throbbing EMS VCS 3 sound with a single-repeat echo. Gilmour played six-string and 12-string acoustic guitars, Wright played the VCS 3, Hammond organ, ARP String Ensemble and Minimoog, and Mason played timpani and cymbals. Gilmour said it was a made-up-in-the-studio piece with no backing track, a collage using tape. He could not reach one vocal line, so the tape was slowed by half a semitone and the line was dropped in. Two versions of the original demo are on the 2025 anniversary reissue.

The band first played it on the 1977 In the Flesh tour, with an animated film by Gerald Scarfe behind them. Because the music had to be synchronized with the film, the band wore headphones and followed a click track.