Watch Jimmy Fallon Lead a Star-Studded Sing-Along to Paul McCartney's 'Wonderful Christmastime'

The Tonight Show Starring Jimmy Fallon

Scarlett Johansson, Seth MacFarlane, Tariq "Black Thought" Trotter, Paul McCartney, Reese Witherspoon, Ahmir "Questlove" Thompson, Jimmy Fallon, Kirk "Captain Kirk" Douglas, Tori Kelly, Matthew McConaughey, and James Poser sing "Wonderful Christmastime" on The Tonight Show Starring Jimmy Fallon on Dec. 20, 2016.

Ever since Jimmy Fallon and Mariah Carey played her classic Christmas hit "All I Want For Christmas Is You" on classroom instruments, it's been hard for the late-night host to even top himself with any other sing-alongs -- that is, until 2016.

In one of his Brady Bunch-style performances, Fallon recruited his Roots band along with the likes of Reese Witherspoon, Matthew McConaughey, Tori Kelly, Seth McFarlane and Scarlett Johansson to sing a harmonious version of Paul McCartney's "Wonderful Christmastime." And to really get into the holiday spirit, of course McCartney tagged along for the caroling bit.

The sing-alongs don't stop there for McConaughey, Kelly, Johansson, Witherspoon and McFarlane, either. They all star in the animated film Sing, which hits theaters Wednesday (Dec. 21). Their animal characters are also featured in the McCartney sing-along, making for one festive video.

Watch Fallon and the gang sing "Wonderful Christmastime" below.