Tell me the song please.
 

Im doing a report for school and im wanting to use a song ive heard in the past in the background. I have no idea the name but i think it would be great. its a pretty cliche war theme song, i believe, with an orchestra or choir just shouting the same sound "ah" over and over with the occasional drawn out "ahhhhh".

could it be carmina burana?
i dunno if it has any words or not but it's usually associated with wars and death and stuff

The Carmina Burana has many, many lyrics. There aren't any war type instrumental bits in it.

You're probably thinking of more specifically 'Ofortuna' from Carmina Burana by Carl Orff... and yes it does have many lyrics, that one in particular is about Fortune...

Oh Fortune, Like the moon you are changeable... etc, etc.

Yeah I think it is Ofortuna also.