Drug that supposedly influenced the Beatles on "Sgt. Pepper's Lonely Hearts Club Band"

LSD

This psychedelic compound, first synthesized in 1938, was famously linked to the Beatles' experimental phase and the vibrant, surreal soundscapes of their 1967 album.

This clue refers to LSD, the hallucinogenic drug often linked to the Beatles' psychedelic phase in the late 1960s. The 1967 album Sgt. Pepper’s Lonely Hearts Club Band is famous for its trippy sound and artwork, which many fans and critics associate with the band’s experimentation with LSD. The answer plays on the drug’s cultural ties to that era of music, especially the Beatles’ creative shift during that time.