On Thursday's The Tonight Show Starring Jimmy Fallon , Jimmy welcomed Billy Joel ahead of his concert at Madison Square Garden Friday night, part of the legendary performer's residency there.
"It's a great place," Joel said of the Garden. "best audience, New York. The building is built on springs...so when you're on stage...the crowd is rocking, the stage goes up and down like an earthquake."
The pair collaborated first on a doo-wop-tinged version of The Tokens ' "The Lion Sleeps Tonight" -- thanks to an iPad app called a "Looper" that allows users to overlay their own voices.
Billy and Jimmy later jammed to Billy's hit "You May Be Right," with both men taking turns on vocals and singing together on the chorus.
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