Jessica and I were playing a game last weekend where I'd play a song from an old movie or video game and she'd try to guess the source. Having not grown up in America, it's got an extra challenge in that most of these games and older movies, she's never seen, so instead she would describe the atmosphere she perceives from the song.
I'd play the Spiderman movie theme by Danny Elfman and she'd explain the violins sound like someone flying through the air and the robotic percussion sounds something like a bugs, usually arriving at something that fits the movie the song is on the soundtrack for.
When we got to the Halo theme, it really made me appreciate the soundtrack of the game. There are basically two competing forces in the theme song. The first and most prevalent is the low strings- what everyone would sing if you asked them to hum the halo theme. Dun dun dun daaaaaah, dun dun dun daaaahhh, dun dun dun daaaaaa, dun dun dun dah dun dun dun dah dah dah. It's a very military style of music. Really gives you the image of troops gearing up and running into battle. The second element of the song is the tribal percussion. With several repeated hits on the uh of 4 and the down beat of 1 "Bah-bum", it makes me imagine something like a mayan tribe around a fire getting pumped up to fight off whoever it was the mayans fought with. You put the two together in the song and you've got the Earth dwelling troops vs the alien tribe dancing on the battlefield.
