Studio Two, EMI Studios, Abbey Road
Having spent much of the day working on mono and stereo mixes for six Revolver songs, The Beatles began a night-time session in which they completed a new song from scratch.
The Beatles spent much of the session rehearsing the song, with at least 25 attempts before the first proper recording attempt. They then taped the rhythm track in three takes. At one point Paul McCartney walked out of the studio following an argument, leading to speculation that George Harrison played bass guitar on the song.
I like the title She Said She Said, which I think was made up on the session. John brought it in pretty much finished, I think. I'm not sure but I think it was one of the only Beatle records I never played on. I think we'd had a barney or something and I said, 'Oh, fuck you!' and they said, 'Well, we'll do it.' I think George played bass.Paul McCartney
Many Years From Now, Barry Miles
The rhythm track had drums, guitar and bass. Onto this John Lennon added his lead vocals, and Lennon and Harrison overdubbed backing vocals. With the four-track tape full, a reduction mix was made, two which Harrison added lead guitar and Lennon added an organ part.Three mono mixes were then made, although these were discarded in favour of a final mix made on the following day.Source: Beatles Bible