The previous day the song had been given the working title Laxton's Superb, a brand of English apple. At some point during this session it became known as I Don't Know - Harrison's reply when asked the name of the song - before I Want To Tell You was eventually chosen.
The only recording needed was a bass guitar part, added by Paul McCartney onto track four of the tape. This was the first time on a Beatles recording that a bass was overdubbed on its own track, although it would become common practice in future months.
I Want To Tell You was then given four mono mixes, the first of which was selected for Revolver. A stereo mix was made on 21 June 1966.
Afterwards five mono mixes of Yellow Submarine were made. The version used on the album features the initial acoustic guitar strum to accompany Ringo Starr's first vocal line, whereas the stereo mix omitted this.