Chorale from Jupiter - Holst
Jupiter has already been mentioned above, but the Chorale is quite different. I you're in a concert band and you've played it then you understand what a special song it is and how it just seems to throb. I'm matching this song as Frodo's theme song. Not because of any references to Jupiter, only that the chords reflect Hope and movement. Here's a link and if you can imagine this song played live in a huge theater, then you can almost feel the 3/4 heartbeat of it.
St. Amant High band concert 2004
EDIT: Actually, I kind of like this year better:
2001