It is arresting to hear the original song idea for "Yellow Submarine," as written and performed by John Lennon. It's only the basic melody and mostly scratch lyrics, but you can get a sense of where this might have gone if it had remained largely in Lennon's hands.
Huffpost writes:
The demo was posted online ahead of Friday's release of an expanded edition of "Revolver," an album widely considered the band's finest work. The new release was remixed by Giles Martin, son of legendary Beatles producer George Martin.
"There's an acceptance of 'OK, I've got this very sensitive and sad song, and Paul's going to turn that into a hit for children,'" Martin told the BBC. "That didn't happen later on 'Abbey Road' or 'Let It Be,' and I think that's the key to 'Revolver.' They absolutely accepted each other's direction."
[H/t RU Sirius/Mondo 2000]