If you're going to attempt to cover a Beatles song you better have an ace up your sleeve, and that's just what Elton John had in the form of backup singer Dr. Winston O'Boogie.

Except there really was no doctor. Instead, that's the fake name John Lennon used for his credits on his friend's single, which went to No. 1 in 1975. (Winston was Lennon's middle name.) The pair recorded several songs together in the early '70s, with the success of one, 'Whatever Gets You Through the Night,' forcing Lennon to make good on a bet and make a rare live appearance with Elton in Madison Square Garden.