During a taping of The Tonight Show Starring Jimmy Fallon, Carrie Underwood teamed up with the show's host for an impromptu performance of a country classic. Readers can press play above to watch the pair take on Kenny Rogers and Dolly Parton's "Islands in the Stream."

Fallon and Underwood's performance of "Islands in the Stream" took place in Central Park in New York City, on Sept. 13. Underwood was appearing on the show to promote her new album, Cry Pretty, and performed her newest single, "Love Wins," but her and Fallon's duet was reportedly an off-the-cuff performance.

"Islands in the Stream" was written by the Bee Gees and released in 1983 as the first single from Rogers' Eyes That See in the Dark album. Fallon's performed the song on his show before: In 2017, he and Miley Cyrus (Parton's goddaughter) sang the song while dressed as Rogers and Parton.

Underwood has been out promoting her new album, which was released on Sept. 14, but she does not have any official tour dates scheduled in support of the project until May of 2018, as she is expecting her second child. On Thursday (Sept. 20), Underwood was inducted into the Hollywood Walk of Fame.

Dolly Parton Through the Years

Unforgettable Carrie Underwood Moments

More From TheBoot