The Beatles recorded the first song for Sgt Pepper's Lonely Hearts Club Band on this day, along with Christmas message for pirate stations Radio London and Radio Caroline.
The session took place from 6.45pm, and ended at 1.50am the following morning. The Christmas messages were the first to be recorded.
The previous year The Beatles had recorded seasonal greetings for pirate stations from their dressing rooms while on tour. In December 1966, having finished touring, they agreed to record new messages in the studio. They were scripted spoken-word items, some of which had a simple Mellotron backing.
All of the messages were recorded live although at one point in the proceedings Paul asked George Martin to feed playback tape echo into the studio as they spoke. George replied, with heavy sarcasm, "Do you want to make a production out of it?" George Harrison then chipped in with "Yeah, let's double-track everything!" and John offered his suggestion, "He can double-splange them! That'd be great!"
Four of the messages, one from each Beatle, were incorporated into the outtake of Christmas Time Is Here Again which was included on the 1995 single Free As A Bird.
The main purpose of the session, however, was the recording of the basic track of McCartney's song When I'm Sixty-Four. Two takes were recorded with McCartney on bass guitar and Ringo Starr on drums, with some electric guitar performed by either Lennon or Harrison towards the end.
Both of the takes were complete, with the second considered the best. McCartney then overdubbed a piano part before the session came to a close.