Interested folks should check out the Internet Movie Database. Play around with the extended search engine. http://us.imdb.com

Not mentioned yet:
Jesus of Montreal, esp opera buskers at finish
The Cook, The Wife, The Thief and Her Lover
Until the End of the World -- esp. the pygmy music
Charlie Brown's Christmas
The Grinch Who Stole Christmas
Chariots of Fire
I've Heard the Mermaids Singing -- final scenes
The James Bond Theme
The Wicker Man -- the final scene (spoiler...a huge group of people singing a joyous harvest song as they burn their middle-aged virgin male victim in a giant wicker man while he sings a Christian hymn). Rocky. Well, I liked that song. The Sting. Nuff said.

I have the feeling this thread is going to bat around in my head for a few days at least.

A TV moment: last? Olympics when the 'Mericans had a young female gymnast who was trying to perform injured, someone had the bright idea to close the night with a collection of snippets of the young gymnasts as they messed up and hurt themselves, playing Amazing Grace simultaneously. It was perfect. Sure didn't expect that from U.S. commercial TV.