So i used to watch this movie when i was younger and i cant remember what it's called, help?

okay, all i really remember was there was a song in it that went "the clarinet the clarinet goes doodley doodley doodley det", (Meg Ryan actually sings the song during christmas time in "You've Got Mail") and at the beginning it shows a car driving up to a house and they are talking or singing about their grandma going to timbucktoo..please help if you know this movie, i have searched for hours trying to find it.