- John Lennon – lead and harmony vocals, rhythm guitar, organ
- George Harrison – lead guitar, backing vocals
- Paul McCartney – piano, bass guitar, backing vocals
- Ringo Starr – drums, tambourine
John Lennon wrote Sexy Sadie just before leaving India. He originally called it Maharishi but George requested the name change.
The Beatles were all disillusioned with the master of Transcendental Meditation. There was an allegation of sexual misconduct by the Maharishi, which turned out to have been untrue, but in all events, Lennon was leaving India with what he called "a bad taste." Sexy Sadie is clearly a symbolic name for the Maharishi.
Smoky Robinson and the Miracles sang a song called I've Been Good to You in which this line appears: "Look what you've done, you made a fool out of someone." Lennon's lyric for Sexy Sadie goes: "What have you done? You made a fool of everyone."
A demo was made at George Harrison's home in May of that year. The song was subsequently recorded on July 19 & 24 and on August 13 & 21, 1968.
The August 13 session was a complete remake of the July work, with eight new takes. John sang lead vocals and played guitar and Hammond organ. Paul sang harmony vocals, played the bass, and a Leslie piano. George played lead guitar and sang harmony vocals. Ringo played drums and tambourine. The finished recording was released on The Beatles (aka The White Album) in November of 1968.
Take 6 (out of 21 from July 19) was made available publicly on Anthology 3. It is a somewhat slower version and does not have the long finale or the piano part.