Studios One/Two, EMI Studios, London
The other Beatles were not present when Paul overdubbed his lead vocal onto "When I'm Sixty-Four" during a 2:30-5:30 afternoon session in EMI Studio One. However, all four were around for the long evening session in Studio Two, 7:00 pm 3 3:40 am. It was during this night that the group set about what is best described as the "orchestral re-make" of Strawberry Fields Forever", recording rhythm track tapes nine through to 24 (there was for some reason no take numbered 19, nor was there an eight). And then, at the end, engineer Geoff Emerick edited together the first three-quarters of take 15 with the last quarter of take 24. An attempt to reduce the resulting edit into take 25 was started but aborted, to be continued the next day. Emerick and Producer George Martin did not attend the entire session, spending the early part of the evening at the premiere of Cliff Richard's feature film, "Finders Keepers".In their place, although he shouldn't really have been so involved, technical engineer David Harries temporarily produced /engineered the Beatles, diving out of the control room when he heard Martin and Emerick returning.
Source: The Beatles Complete Chronicle