Vince Guaraldi's score of course. The title song sung by Rod McKuen is special, too.
John Scott Trotter's orchestrations deserve mention. They capture a wistful, melancholy tone that fit Guaraldi's music perfectly, and the instrumental pieces that Trotter composed ("Cloud Dreams", "Bus Wheel Blues", "Blue Puck"—the titles give away which parts of the film they play under) are standouts.
Big-Lipped Alligator Moment: Tons. It's kind of justified, considering that it was the first full-length Peanuts movie, but it sort of goes overboard on it. The skiing scene with Snoopy in New York City and Schroeder playing that Beethoven piece are major ones.
Crowning Moment of Awesome: As anyone who has seen the special will tell you, this is pretty much the highpoint of Charlie Brown's childhood (aside from getting a love note from the Little Red Head Girl), with Charlie Brown carried around by his classmates as they sing his praises as he has rightfully won the school championships in spelling. Snoopy even salutes him as he arrives home.
Ear Worm: "Champion Charlie Brown". You'll find yourself humming it a lot, partly because it's sung when Charlie's at his high point. The song even makes a cameo during the opening Cinema Center Films logo.
Failure is a part of life and it's unavoidable at times.
Another Aesop is "Time heals all wounds (no matter how badly you mess up.)"
Linus: Well, I can understand how you feel. You worked hard, studying for the spelling bee, and I suppose you feel you let everyone down, and you made a fool out of yourself and everything. But did you notice something, Charlie Brown?
Charlie Brown: What's that?
Linus: The world didn't come to an end.
Nightmare Fuel: The Beethoven sequence. Sure, it might be lovely to watch for someone who appreciates the artistic value, but otherwise....
Society Marches On: Charlie Brown twice says to himself, "It's Sydney or the bush," which in the U.S. was a very short-lived idiom. It makes more sense in Australia.
Tear Jerker: While not as soul-crushing as Snoopy, Come Home, the whole movie has a pretty melancholic tone. The basic plot is Charlie Brown dealing with the unrelenting misery and failure that is his life, getting a Hope Spot when he gets a chance at a regional spelling bee, and returning in disgrace after he loses.
The Woobie: Oh God, Charlie Brown. The whole movie will have you wanting to give him a hug.
It's also hard not to feel sorry for Linus without his blanket (which he gave to Charlie Brown, before the latter left for the spelling bee).