Aha. I'm showing my age. I didn't know there was a "Peanuts" movie. I was talking about the tune "Linus and Lucy" which was the theme for the original animated TV show "A Charlie Brown Christmas."

(And I shouldn't have called it a song, as there are no words).

Perhaps-fun stuff:

Linus and Lucy was recorded by the Vince Guaraldi Trio back in 1964.

They're all dead now, which is a shame.

But there's a brilliant modern recording, from 2016, that features the original drummer, Jerry Granelli: https://www.youtube.com/watch?v=OODA_K5hxyc

And it's definitely worth spending some time to give it a watch/listen. There's a lot more to that little tune than most people probably realize.