The 10 stereo mixes of Sgt Pepper's Lonely Hearts Club Band (Reprise) were made in the control room of Studio Three, from 5-6.15pm. George Martin was not present, so they were created by balance engineer Geoff Emerick and tape operator Richard Lush.
Martin was present for the evening recording session, which took place from 7pm to 2.15am. The Beatles returned to the original take three from 13 February 1967, erased two of the tracks and overdubbed bass guitar on one and glockenspiel, whistling and trumpet on the other.
In the studio were producers of the Yellow Submarine film, the soundtrack for which the song was intended for.
The film producers were wandering around the studio and they had to sort of go along with this - I saw some very sad faces while I'm playing this trumpet.
The Beatles then returned to take 11, a reduction mix made on 14 February, and George Harrison sang two lead vocals. He was joined by McCartney on vocals and trumpet for one of the takes. One of the drum tracks for take 11 was replaced with piano, timpani, Mellotron and organ.
The two versions of Only A Northern Song - takes 3 and 11 - were mixed together during the following day's session.