Paul McCartney, Scarlett Johansson, and the Roots Sing Wonderful Christmastime

A member of the Avengers is getting into the Christmas Spirit with The Tonight Show host Jimmy [...]

A member of the Avengers is getting into the Christmas Spirit with The Tonight Show host Jimmy Fallon, his legendary band The Roots, and musical icon Paul McCartney.

Black Widow actress Scarlett Johansson, who was confirmed for Avengers: Infinity War earlier today, joined the impressive line up to perform "Wonderful Christmas" on NBC's Tonight Show this week. She wasn't alone. Also joining to sing were Matthew McConaughey, Reese Witherspoon, Tori Kelly, and Seth McFarlane in the a cappelle rendition.

Johansson's fellow guests were not random. The cast appearing in Fallon's new song are her co-stars in the upcoming animated film Sing.

In Sing, McConaughey's dapper Koala Buster Moon presides over a once-grand theater that has fallen on hard times. An eternal optimist, and a bit of a scoundrel, he loves his theater above all and will do anything to preserve it. Facing the crumbling of his life's ambition, he takes one final chance to restore his fading jewel to its former glory by producing the world's greatest singing competition. Five contestants emerge: a mouse, a timid elephant, a pig, a gorilla and a punk-rock porcupine.

The fun video is only a taste of what to expect from Sing. Universal Studios showed off a impressive chunk of the film at CinemaCon in April. The soundtrack includes wide variety songs from top artists such as Drake and Frank Sinatra.

As for Johansson, specifically, the holiday season and end of the year don't mark and signs of slowing down. The action-star actress is front and center for the Ghost in the Shell big screen adaptation in addition to taking on Thanos in what we'll surely be the largest culmination of the Marvel Cinematic Universe in 2018.

Sing hits theaters December 21, 2016.