​Watch Paul McCartney, Jimmy Fallon and the Cast of 'Sing' Do "Wonderful Christmastime"

​Watch Paul McCartney, Jimmy Fallon and the Cast of 'Sing' Do "Wonderful Christmastime"
Mullet-ed Mannequin Challenge master Paul McCartney stopped by The Tonight Show Starring Jimmy Fallon last night (December 20) to share some festive musical fun.
 
The former Beatle was joined by host Jimmy Fallon, the show's house band the Roots, and the cast of the new animated flick Sing — including Reese Witherspoon, Scarlett Johansson, Matthew McConaughey, Seth MacFarlane and Tori Kelly — for a spirited a cappella rendition of Macca's holiday classic "Wonderful Christmastime."
 
The tune gets matched with visuals that find the singers in Brady Bunch-esque squares, which you can see for yourself in the player below.
 

Pre-order the super deluxe edition of McCartney's 1989 solo album Flowers in the Dirt here.