What song is this?

I remember it being used on the trailer for the original Matrix movie back in 1998/9 although it does not show up on the movie soundtrack listing on the Internet Movie Database. Basically it’s a bunch of monks chanting while a horn is slowly playing in the background. Any idea what it is? Any help is appreciated.

I want to say Gregorian monks… but so far I have yet to find it.

This trailer? They’ve got some Gregorian-style stuff with trombone about 3/4 of the way through it (right after “Kansas is going bye-bye…”). No particular piece, probably not even real voices (there aren’t any words enunciated, so it’s probably all synthesizer).

It sounds a lot like Enigma. They have like 4 albums out but i’ve only heard the first. They use a lot of synthetic horns and gregorian chants.