On her new album, 'Partners,' Barbra Streisand teams up with some of the greatest voices in music. Her latest duet "partner"? Jimmy Fallon!

During an appearance on 'The Tonight Show' last night (Sept. 15), the legendary singer was joined by the comedian to perform a medley of tracks from the new album. Seeing as Barbra recorded the tracks with vocals from Elvis Presley, Blake Shelton and more, it only seemed appropriate that Jimmy dress up as each singer he impersonated.

Barbra sounded incredible, of course, but Jimmy added some levity with his hilarious, spot-on impressions. (He even threw in an Elvis-esque "Thank you very much"!) The pair totally played off of each, making this a very memorable performance.

It's also worth nothing that this is Barbra's first late night appearance in 50 -- yes, 50 -- years! According to Us Weekly, she last appeared on Johnny Carson's 'Tonight Show' in 1967.

Watch Barbra and Jimmy blow the audience away with their medley of duets in the video above!