Sara and I have been playing this duet since we were 11 and nine years old, and we still play it at least once every time we're together and in the presence of a piano. It's called the Polka Dot Polka, and clearly it invites dancing.
Well, Hallie danced. Lily danced, grocery shopped, and cried for someone to give her access to the guitar.
Oh, and Will actually filmed this video - he's obviously going to be the next Steven Spielberg. Or Dawson Leary.