Carl Orff's 'Carmina Burana' sounds like a song that would fit nicely. But when translated, it just loses its magic.
I wish I didn't ask Sharku about that now. Plus it seems slightly cliche, as does 'Ride of the Valkyries'. A shame, I like them both.
'Dual of the Fates', the song in Starwars Episode 1 was pretty good. I don't know the names of any Celtic songs, but they would probably go along with all of this.
'The Brother of Sleep'? hmm, I was thinking Bach, but 'Sleepers Wake' or 'Come Sweet Death'(?) instead. I don't think I have 'The Brother of Sleep'
Thus even as Eru spoke to us shall beauty not before conceived be brought into Eä, and evil be good to have been