McCartney sat down at the piano for a performance of "My Valentine."
The singer joined in for a "Holiday Pageant" sketch with Short, that led into a performance of "Wonderful Christmastime."
The performance of "Wonderful Christmastime" featured the New York City Children's Chorus. The chorus also opened the show with "Silent Night," as a tribute to the victims of the shooting at Sandy Hook Elementary School.
Finally, McCartney once again joined forces with the surviving members of Nirvana for an electric performance. The collaboration first took place at New York's 12-12-12 concert, benefitting victims of Hurricane Sandy. On 'SNL' McCartney, Dave Grohl, Krist Novoselic, and Pat Smear played a new track, "Cut Me Some Slack." A video of the performance will be added once it becomes available.