It was good fun, but I wouldn't like to do it for a living.
On November 28, 1974 a nervous John Lennon joined Elton John onstage at Madison Square Garden to pay off a bet he lost. After they recorded "Whatever Gets You Through the Night" that Summer, Elton bet Lennon it would be the former Beatle's first #1 hit. Lennon agreed to appear on stage with Elton should he lose. And lose, he did. The song hit #1 in November 1974.
They performed "Whatever Gets You Through the Night" and Elton's ten day old single, "Lucy on the Sky With Diamonds", which Lennon had helped Elton John record under the pseudonym Dr Winston O'Boogie. The final song was another Beatles cover, " I Saw Her Standing There", introduced in this way by Lennon:
I'd like to thank Elton and the boys for having me on tonight. We tried to think of a number to finish off with so I can get out of here and be sick, and we thought we'd do a number of an old, estranged fiancé of mine, called Paul. This is one I never sang, it's an old Beatle number, and we just about know it.
This was the last time Lennon ever appeared in a major concert.
A day earlier Lennon's "estranged fiancé" and his wife Linda appeared onstage with Rod Stewart to sing "Mine For Me", a song he'd written for Stewart's most recent album Smiler.