Every Christmas, on the same Late Show episode where Dave and Jay Thomas try to knock the meatball off of the Christmas tree, Paul Shaffer does his impersonation of Cher singing "O, Holy Night." He didn't do it last night on the show, but he did do it, and CBS has it as a web exclusive.

By the way, Thomas didn't even get to throw a football last night. Dave knocked the meatball off before he could even get a football in his hands.

[Watch clips and episodes of The Late Show and other shows at SlashControl.]

If you didn't see Studio 60's Christmas episode, then you should. Not only was it one of the show's best, but it featured a musical performance by New Orleans musicians displaced by Hurricane Katrina that's sure to put a lump in your throat. The musicians were led by Troy "Trombone Shorty" Andrews in an original arrangement of "O Holy Night." You hear carols a thousand times, and after awhile, they lose the power to move you. This performance brought all that power back. You can now download the track as a free MP3 from NBC's Studio 60 website or iTunes.