Paul McCartney returned to Saturday Night Live this past weekend, taking part in a skit with host Martin Short and performing three songs. Two of those songs – “My Valentine” from 2012′s Kisses On The Bottom and his seasonal classic “Wonderful Christmastime” – were easy to predict. But the third (actually, the second one he performed) saw him do an artistic 180-degree turn, as McCartney reprised his role as the singer of “Sir-vana.”

Of course, “Sir-vana” is not technically a band, but the idea is real. After rumors swirled last week, McCartney and Nirvana’s surviving members – drummer Dave Grohl, bassist Krist Novoselic and their one-time touring guitarist Pat Smear – debuted at Wednesday’s 12.12.12 Concert. During both performances (12.12.12 and SNL), the group performed “Cut Me Some Slack,” the first single off the soundtrack for Grohl’s upcoming documentary, Sound City. Shortly after the SNL performance, the studio version of “Cut Me Some Slack” was released via Sound City‘s official YouTube channel and has now hit iTunes, ahead of the album of official 12.12.12 recordings.

As for the rest of Macca’s SNL stint (including Joe Walsh on guitar duties for “My Valentine”), his skit with Martin Short is not to be missed. The two played a musical duo named Caleb and Monty, with Short as the singer and McCartney playing the triangle. Short’s character wouldn’t let McCartney’s character sing, yelling, “You don’t sing because you can’t sing! I have the million dollar voice! You don’t!” After McCartney kept missing his cues, Short quit the duo. The set was then pulled down to reveal McCartney’s band, at which point Sir Paul joined them (and a children’s choir) for his “Wonderful Christmastime.”

– Brian Ives & Jillian Mapes, CBS Local