Jimmy Fallon, Paul McCartney and Star-Studded Cast Sing 'Wonderful Christmastime' (Video)
YouTube/The Tonight Show
See More of Jimmy Fallon's Craziest 'Tonight Show' Moments

Jimmy Fallon, The Roots and Paul McCartney had a special surprise for the viewers of Tuesday night's "Tonight Show."

Performing his '80s hit, "Wonderful Christmastime," Fallon and The Roots joined alongside special appearances by Scarlett Johansson, Matthew McConaughey, Reese Witherspoon, Seth MacFarlane, and Tori Kelly. The animated cast of "Sing" also joined the A-list celebs in their rendition of the McCartney hit.

Watch the video (below) and see more of Jimmy Fallon's craziest "Tonight Show" moments in the gallery (above).