Name that tune in Episode 2
20 minutes into the episode entitled The Lady, Clark's family is decorating the Christmas tree, and I think Clark rushes in and says "Well that's it, then Christmas is cancelled". There is a tune playing in the background, presumably a Christmas tune.
What is the title of this tune ? I've heard the tune in only two other places, and have been trying to identify it for the past 15 years. Any useful help appreciated.