From Wikipedia:
"Maggot Brain" was recorded in one take when George Clinton, under the influence of LSD, told guitarist Hazel during the recording session to play as if he had been told his mother was dead:[5]Clinton explained "I told him to play like his mother had died, to picture that day, what he would feel, how he would make sense of his life, how he would take a measure of everything that was inside him."[9] Though several other musicians performed on the track, Clinton largely faded them out of the final mix so that the focus would be on Hazel's guitar. Hazel utilized fuzz and wah effects, inspired by his idol Jimi Hendrix; Clinton subsequently added delay and other effects in mixdown, saying "I Echoplexed it back on itself three or four times. That gave the whole thing an eerie feel, both in the playing and in the sound effects."[9] Critics have described the solo as "lengthy, mind-melting" and "an emotional apocalypse of sound."[10]