Final answer:
The song 'Lucy in the Sky with Diamonds' was inspired by a painting done by John Lennon's son Julian, depicting a classmate named Lucy, not by LSD or psychedelic experiences.
Step-by-step explanation:
The actual inspiration behind the song “Lucy in the Sky with Diamonds” by The Beatles was a painting by Julian Lennon, John Lennon’s son. Contrary to popular belief at the time of the song's release, which suggested that the song was a reference to the hallucinogenic drug LSD (“d-lysergic acid diethylamide”), the song was actually inspired by a drawing Julian created. John Lennon explained that the imagery in the song was inspired by Julian’s drawing of a classmate named Lucy, accompanied by the fantastical imagery Lennon associated with childhood. Although the song has long been associated with psychedelic experiences and the culture of the 1960s, the Beatles have consistently denied any intentional link between the song’s title and the drug.