The day was divided into two discrete sessions: the first began at 2.30pm and ended at 7.15, and the second began an hour later and finished at 1.30am the following morning.
It began with the overlaying of various tape loops onto Tomorrow Never Knows, which at the time had the working title Mark 1. The backing track had been recorded on the previous day.
Each of The Beatles brought in tape loops made on their home Brennell machines. Five of the loops were placed onto different mono tape machines, with studio staff using pencils to keep them taut.
Balance engineer Geoff Emerick, in the control room of Studio Three, created a live mix from the five feeds which was recorded onto track three of the four-track tape; the basic rhythm track had previously been recorded onto tracks one and two, along with a dropped-in backwards guitar solo.
We did a live mix of all the loops. All over the studios we had people spooling them onto machines with pencils while Geoff did the balancing. There were many other hands controlling the panning.
It is the one track, of all the songs The Beatles did, that could never be reproduced: it would be impossible to go back now and mix exactly the same thing: the 'happening' of the tape loops, inserted as we all swung off the levers on the faders willy-nilly, was a random event.
The first loop resembled the sound of a seagull, but was in fact a distorted guitar guitar speeded up. It appears five times in the final mix. The second loop was a sustained chord, and appears eight times.
Loop three is heard seven times, and is a high string sound heard at different pitches. It is twice heard being slowed down. The fourth loop is another string sound which appears eight times, and can be heard panning from left to centre just before the guitar solo.
The final tape loop on Tomorrow Never Knows was the sound of a wineglass rim being rubbed, and appears just once from 0'53"-0'56". The song was completed on 22 April with the addition of more vocals, guitar, organ, tambourine and piano.
We ran the loops and then we ran the track of Tomorrow Never Knows and we played the faders, and just before you could tell it was a loop, before it began to repeat a lot, I'd pull in one of the other faders, and so, using the other people, 'You pull that in there,' 'You pull that in,' we did a half random, half orchestrated playing of the things and recorded that to a track on the actual master tape, so that if we got a good one, that would be the solo. We played it through a few times and changed some of the tapes till we got what we thought was a real good one.
Many Years From Now, Barry Miles
During the day's second session The Beatles began work on Got To Get You Into My Life. They recorded five takes, the last of which was released on 1996's Anthology 2. The recording featured harmonium, drums, bass guitar and acoustic guitar.
Before the end of the session McCartney overdubbed lead vocals, and backing vocals and tambourine were added by McCartney, Lennon and Harrison. However, this attempt was scrapped in favour of a remake on the following day.