<P> "Tomorrow Never Knows" is a song by the English rock band the Beatles, released as the final track on their August 1966 album Revolver . Credited as a Lennon--McCartney song, it was written primarily by John Lennon . The song has a vocal filtered 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 a constant but non-standard drum pattern . It marked the first recorded use of reversed sounds in a pop song . "Rain", which was released showcasing the technique three months earlier, was recorded after . </P> <P> "Tomorrow Never Knows" is considered one of the greatest songs of its time, with Pitchfork Media placing it at number 19 on its list of "The 200 Greatest Songs of the 1960s" and Rolling Stone placing it at number 18 on its list of the 100 greatest Beatles songs . </P> <P> John Lennon wrote the song in January 1966, with lyrics adapted from the book The Psychedelic Experience: A Manual Based on the Tibetan Book of the Dead by Timothy Leary, Richard Alpert, and Ralph Metzner, which was in turn adapted from the Tibetan Book of the Dead . Although Peter Brown believed that Lennon's source for the lyrics was the Tibetan Book of the Dead itself, which, he said, Lennon had read whilst under the influence of LSD, George Harrison later stated that the idea for the lyrics came from Leary, Alpert, and Metzner's book; Paul McCartney confirmed this, stating that when he and Lennon visited the newly opened Indica bookshop, Lennon had been looking for a copy of The Portable Nietzsche and found a copy of The Psychedelic Experience that contained the lines: "Whenever in doubt, turn off your mind, relax, float downstream". </P> <P> Lennon bought the book, went home, took LSD, and followed the instructions exactly as stated in the book . The book held that the "ego death" experienced under the influence of LSD and other psychedelic drugs is essentially similar to the dying process and requires similar guidance . This is a state of being known by eastern mystics and masters as samādhi (a state of being totally aware of the present moment; a one - pointedness of mind). </P>

Where did john lennon get lyrics for the revolutionary tomorrow never knows track from revolver