According to Mark Lewisohn, “John Lennon was officially accredited as producer of a Beatles session for the first time on this day.” He then adds,

Except that this wasn’t really a Beatles recording. True, Lennon/McCartney composed the song (and even had it copyrighted), a jaunty ditty titled “Shirley’s Wild Accordion.” True, towards the end of the session Ringo climbed behind his drum kit and tapped out a little beat and Paul McCartney added maraca and a little background yelling. [But] its fruits were not even released on record because the song was used solely as incidental music in the Magical Mystery Tour film. The star of the song, the main instrumentalist, was the accordion player named in the title, Shirley Evans, accompanied by her musical partner Reg Wale.

This piece I found on YouTube purports to be “Shirley’s Wild Accordion”; whether it’s genuine or not, I don’t know.  Judge for yourself:

In non-accordion-related news, two of George’s songs — “It’s All Too Much” and “Blue Jay Way” — were mixed today. Given that these two songs were written and recorded around the same time, I wonder why the loud and expansive “Too Much” wasn’t used in Magical Mystery Tour rather than the relatively dour “Blue Jay.” It seems to make more cinematic sense. But then again, it probably wouldn’t have helped much.