What's the title and who's the artist of this song?

Okay, I'm not even sure it has lyrics, so I'll just describe it. I've heard it most recently in Shrek The Halls when Shrek is running through the snow at the start. But I've heard it somewhere (or something similar to it) already before. It's like a gothic da-vinci-code-running-through-the-corrid… song sung by a full choir.