Main theme music or not, this is what I've got out of the theme so far:

Quote Originally Posted by Heavensward Trailer Theme
Beneath the gazing stars...
Vales deep, and forest dark...
Between my loyal lands of blessed earth!
Out fast; and to your feet...
One path; one good and great...
Yet ever do alighting souls point Heavensward!
Memories and our song...
Only the last four words of the third line, and first word of the fourth line, do I have any doubts about. I don't think I'll contribute much to guessing at lore from this song, but it certainly sounds very Ishgardian, what with souls going Heavensward (to Halone's Hall), and the talk of only one path.