There were two scheduled sessions. The first took place from 2.30-5.30pm, and saw Paul McCartney overdub lead vocals onto When I'm Sixty-Four. None of the other Beatles were present.
The second session began at 7pm and continued until 3.40am the following morning. Although The Beatles had completed a version of Strawberry Fields Forever on 29 November 1966, John Lennon was dissatisfied with the results and had asked George Martin to score it for brass and strings.
The first task was to re-record the rhythm track. This took 15 attempts, numbered 9-24 with no take 19. Only nine of the takes were complete, and were faster than the previous attempts.
George Martin and Geoff Emerick arrived late to the studio as they had tickets for the première of the Cliff Richard film Finders Keepers. As The Beatles were keen to start recording, technical engineer Dave Harries oversaw the early part of the session.
Soon after I had lined up the microphones and instruments in the studio that night, ready for the session, The Beatles arrived, hot to record. There was nobody else there but me so I became producer/engineer. We recorded Ringo's cymbals, played them backwards. Paul and George were on timps and bongos. Mal Evans played tambourine, we overdubbed the guitars, everything. It sounded great. When George and Geoff came back I scuttled upstairs because I shouldn't really have been recording them.
The Complete Beatles Recording Sessions, Mark Lewisohn
Towards the end of the session an edit was made of the work so far. The first 2:24 of take 15 was combined with the latter part of take 24, which featured Lennon muttering phrases including "Cranberry sauce" and telling Starr to calm down. An attempt at a reduction mix was then made, but was redone during the following day's session.
Part of the rhythm track was included on Anthology 2 in 1996.