As website Dangerous Minds notes, where the video first appeared, the story behind the disc was chronicled in Richie Unterberger’s book The Unreleased Beatles: Music and Film:
For years, it had been reported that Paul McCartney recorded an album at home around Christmas 1965 specifically for the other Beatles. Supposedly, it included singing, acting, and sketches, and only three copies were pressed, one each for John, George, and Ringo. In a 1995 interview with Mark Lewisohn, Paul confirmed this in some detail, explaining, “Yes, it’s true. I had two Brenell tape recorders set up at home, on which I made experimental recordings and tape loops, like the ones in ‘Tomorrow Never Knows.’ And once I put together something crazy, something left field, just for the other Beatles, a fun thing which they could play late in the evening. It was just something for the mates, basically.”
"It was called Unforgettable and it started with Nat ‘King’ Cole singing ‘Unforgettable,’ then I came in over the top as the announcer” ‘Yes, unforgettable, that’s what you are! And today in Unforgettable...’ It was like a magazine program: full of weird interviews, experimental music, tape loops, some tracks I knew the others hadn’t heard, it was just a compilation of odd things. I took the tape to Dick James’s studio and they cut me three acetate discs. Unfortunately, the quality of these discs was such that they wore out as you played them for a couple of weeks, but then they must have worn out. There’s probably a tape somewhere, though.
Listen to the album below: