See Paul McCartney, 'Sing' Cast Perform 'Wonderful Christmastime' on 'Fallon'

'Sing' cast – including Matthew McConaughey, Scarlett Johansson, Reese Witherspoon – join for a cappella rendition of McCartney hit on 'Tonight Show'

Paul McCartney teamed with the Roots, Jimmy Fallon and the 'Sing' cast to perform an a capella version of "Wonderful Christmastime."

Paul McCartney fronted an all-star, a cappella version of his holiday classic, the 1979 synth-pop gem "Wonderful Christmastime," Tuesday on The Tonight Show. Jimmy Fallon and the cast of computer-animated musical comedy Sing – Scarlett Johansson, Matthew McConaughey, Tori Kelly, Reese Witherspoon, Seth MacFarlane – added vocal cameos, backed by the Roots' harmonies and beatboxing.

The pre-filmed piece unfolded like the opening credits to The Brady Bunch, with each singer's head occupying its own holiday-themed box. Midway through, the Sing actors briefly transformed into their animated characters.

Last December, Fallon and the Roots created a similar a cappella video to promote Star Wars: The Force Awakens. Daisy Ridley, Oscar Isaac, John Boyega, Adam Driver, Gwendoline Christie, Lupita Nyong'o, Carrie Fisher, Chewbacca and a handful of droids united with Fallon to tackle several of John Williams' classic themes, including the iconic opening music.

Paul McCartney recently announced an expansive reissue of his 1989 LP, Flowers in the Dirt, featuring rare demos with Elvis Costello.