Barbara Streisand was 21 when she last appeared on The Tonight Show. Johnny Carson was the host, of course. Leave it to the amazing Jimmy Fallon to get Barbara back on the show. She is promoting a new album, Partners, where she sings with some amazing performers. Watch and see how it played out last night. Hilarious, and awesome. 

Jimmy Fallon wouldn't be Jimmy if he didn't play some dress up and do some singing of his own. He stood in for Elvis, Blake Shelton and Michael Bublé in a medley of duets, and did a great job. He even gets praises from Streisand along the way!