"Tomorrow Never Knows" is a song by the English rock band the Beatles, released as the final track on their 1966 studio album Revolver. Credited as a Lennon–McCartney song, it was written primarily by John Lennon. The song has a vocal put through a Leslie speaker cabinet (which was normally used as a loudspeaker for a Hammond organ). Tape loops prepared by the Beatles were mixed in and out of the Indian-inspired modal backing underpinned by Ringo Starr's constant but non-standard drum pattern.