Timothy Leary before a crowd of university students during a lecture tour in 1969. Pitchfork placed the track at number 19 on its list of 'The 200 Greatest Songs of the 1960s', and Rolling Stone ranked it at number 18 on the magazine's list of the 100 greatest Beatles songs. On release, the song was the source of confusion and ridicule by many fans and journalists it has since received praise as an effective representation of a psychedelic experience.

It also introduced lyrical themes that espoused mind expansion, anti-materialism and Eastern spirituality into popular music. 'Tomorrow Never Knows' was an early and highly influential recording in the psychedelic and electronic music genres, particularly for its pioneering use of sampling, tape manipulation and other production techniques. The song's backwards guitar parts and effects marked the first use of reversed sounds in a pop recording, although the Beatles' 1966 B-side ' Rain', which they recorded soon afterwards using the same technique, was issued over three months before Revolver. Part of Lennon's vocal was fed through a Leslie speaker cabinet, normally used for a Hammond organ. It features an Indian-inspired modal backing of tambura and sitar drone and bass guitar, with minimal harmonic deviation from a single chord, underpinned by a constant but non-standard drum pattern added to this, tape loops prepared by the band were overdubbed 'live' onto the rhythm track. The Beatles' recording employed musical elements foreign to pop music, including musique concrète, avant-garde composition and electro-acoustic sound manipulation. When writing the song, Lennon drew inspiration from his experiences with the hallucinogenic drug LSD and from the 1964 book The Psychedelic Experience: A Manual Based on the Tibetan Book of the Dead by Timothy Leary, Richard Alpert and Ralph Metzner. The song marked a radical departure for the Beatles, as the band fully embraced the potential of the recording studio without consideration for reproducing the results in concert. It was released in August 1966 as the final track on their album Revolver, although it was the first song recorded for the LP. ' Tomorrow Never Knows' is a song by the English rock band the Beatles, written primarily by John Lennon and credited to Lennon–McCartney.

Soft sitar background music