The microtonal synthesizer loop heard throughout "Music for Pylons" is sampled from "Karn Evil 9, Third Impression" from the album Brain Salad Surgery by Emerson, Lake, and Palmer. The sample is taken from around 8:40 and has been slowed down considerably.[1][2]
The drums are sampled from "Cocaine Sex (Turbo Lust Mix)" by "Renegade Soundwave".[3][4]
The snare drum sample may have been taken from "When the Levee Breaks" by Led Zeppelin.