It's the making of John's Imagine album videotaping him recording every song on the album plus a few out-of-studio tidbits. George even guest stars a few songs which did include him on the actual album.
I borrowed it from the library and I loved it! You can find it here on Youtube.
[Warning: A few swear words on Oh Yoko! (naked scenes), Gimme Some Truth, Oh My Love, between How Do You Sleep? and How?]