Meet Me in St. Louis (1944)

Continuity mistake: The levels of soup in people's bowls change during the dinner scene at the beginning.

Agnes Smith: Katie, where's my cat?
Katie the Maid: I don't know... a little while ago, she got in my way and I kicked her down the cellar steps. I could hear her spine hitting on every step.
Agnes Smith: Oh, if you killed her, I'll kill you! I'll stab you to death in your sleep, then I'll tie your body to two wild horses until you're pulled apart.
Katie the Maid: Oh, won't that be terrible, now? There's your cat.

Trivia: The address - 5135 Kensington Ave. - sung about by Judy Garland in "The Boy Next Door" was a real St. Louis address located near the World's Fair grounds. The house, torn down just a few years ago, was a row house, though, not the sprawling Victorian mansion shown in the film.

Question: What is the name of the last song they dance to at the Christmas dance? I know I've heard it before, but I can't put a name on it.

Jennifer 1