Skyrim talk:Heddic's Volunruud Notes

What "old hymns" had truth to them? Is this just what Heddic has heard, or are there books referring to Volunruud? I've yet to be there, and I'd like to roleplay my character into going there according to these "hymns", not just "happening to arrive at the doorstep for no apparent reason". If there are no other references than Heddic's notes, well, I guess I have to go to tavern to "hear" one of these hymns. :P