Help Me find this Lord of The Rings music

[Brother Oni]

Ergh. it'll be hard to remember. but I was still young at the time. but the Xbox and Fellowship of the Ring came out pretty much the same year right?

2001, yes.

it was that far back...I also definitely heard it before I ever saw Return of the King, even in its first version, maybe even The Two Towers, those that is less sure....

I was going to say it was only 13 years ago, but that speaks to more how old I am than anything else.

but I never heard it in the films themselves, so.....its very likely it was never recorded so, as you say

You mis-understand - if it wasn't recorded for Lord of the Rings movies, it was most likely recorded for something else and just labelled up as Lord of the Rings by your brother.
It'd be like searching for Europe's The Final Countdown in the Shinseiki Evangelion OST because somebody made an AMV of it.

So far, we have a choir singing in an non-English language (possibly Quenya - I apologise in advance if you actually know it was Quenya), a flute, drums (and two lines which sound like "turi turi turi anay anay aaaah" and "anah unay anay aah, wei-eeeeeeiiii, anah, anay, anah, anay-aaaaaaaayyyyy" ).

but now I have a bigger problem. if I type in "lord of the rings music" into google, I always get the Howard Shore stuff. so I have no way of finding any the custom stuff and sorting them out. especially as far back as like, 2001 or 2002....

Try "Lord of the rings music -shore" to eliminate anything by Howard Shore from your search.
I've just plugged that in and found a variety of LotR inspired music, for example: Music Inspired by The Lord of the Rings.

The wiki page of Works Inspired by Tolkien has a music section: link.