Ok, this piece is played during like every big battle in a movie trailer ever; it’s basically an ominous choral singing (with a little percussion):
ah-ah-ah-ah bum-BUM ah-ah-ah-ah bum-BUM ah-ah-ah-aaaaaah-ah-ah-ah (then it repeats, but in a higher key)
This has been bugging me forever. Sorry that the, uh, visual representation is not exactly clear. 
This piece is really prevalent, so hopefully someone will know what I’m talking about…
I’m pretty sure you’re thinking of Orff’s score to Carmina Burana, which was based on medieval poems from a Benedictine abbey in Germany.
http://www.amazon.com/exec/obidos/tg/detail/-/B000001GQP/002-0929362-8679252?vi=glance (you can hear a sample of it there–specifically, the first song, “Fortune, Empress Of The World, O Fortune”
Ah, thanks a lot for unloading my subconscious; that’s precisely it. 
And to throw in a bonus question to any remaining interlopers:
My mom wants to know the name of the song played by the flutist (sorry, can’t clarify, don’t remember the movie myself :)) in Mr. Holland’s Opus…any ideas?
You say Carmina,
And I say Burana,
You say Carmina,
And I say Burana,
Carmina!
Burana!
Carmina!
Burana!
Let’s call the whole thing off!