Last night Pentatonix hit Jimmy Kimmel Live! with a spot of a cappella. Which way did they go with their signature sound? To the snowy Land of Xmas, with "God Rest Ye Merry Gentlemen," which appears as track two on their new album A Pentatonix Christmas—and on our very own Best Holiday Songs of 2016 So Far list. The LP debuted at No. 3 on the Billboard 200.

Watch the live performance of "God Rest Ye Merry Gentlemen" above. And while we're here, we might as well tell you Ryan Gosling, as musical as he is beautiful, was on Kimmel, too. He played piano, in the form of a new scene from La La Land.

On Dec. 14, NBC will air A Pentatonix Christmas Special, the group's first holiday show. The hourlong program will feature Kelly Clarkson and Reba McEntire.

Watch a Fuse report about the rise of a cappella in the mainstream: