'Sing' Cast Does Some Holiday Harmonizing With Paul McCartney, Jimmy Fallon, and The Roots on 'The Tonight Show'

An industrious koala bear (voiced by Matthew McConaughey) tries to save his theater from being shut down by staging an American Idol-style singing contest — which, in turn, gives a variety of the neighborhood’s animated animals the chance to fulfill their lifelong karaoke dreams — in Sing, which is set to be one of the holiday season’s biggest hits. To get us all in a crooning mood, the movie’s voice cast took to The Tonight Show to belt out a rendition of a modern Yuletide classic — and the film’s pig, porcupine, elephant, and mouse got a little bonus help from a Beatle.

Related: ‘Sing’ Review: A Veritable Farmyard of Fun

In the clip (watch the full performance below), Jimmy Fallon and his house band, The Roots, kick off a joyous a cappella version of Paul McCartney’s “Wonderful Christmastime” in divided-screen graphics à la the opening of The Brady Bunch. They’re soon joined by Sing-ers — including McConaughey, Reese Witherspoon, Scarlett Johansson, Seth MacFarlane, and Tori Kelly — as well as those actors’ animal counterparts from the film. And since they’re all singing a McCartney song, it’s only fitting for him to chime in as well.

For setting the Christmas mood, it doesn’t get much better. Sing is in theaters now.

‘Sing’ Cast and Co.’s ‘Wonderful Christmastime’: Watch the full ‘Tonight Show’ segment: