The Harp of the Grey Rose — Charles de Lint

Throughout the Celtic lands they would call him…
SONGWEAVER!

But for now he was merely Cerin of Wran Cheaping -- an orphaned youth of seventeen years raised by a wildland witch. Then, in the light of the Mead Moon, he encountered the maid of the Grey Rose -- the lone survivor of the war that devastated the Trembling Lands and promised bride of Yarac Stone-slayer, the feared and terrible Waster. A helpless captive of the evil being to whom she'd been hand-fasted, the mysterious beauty enslaved Cerin's heart, drawing him into a world both dark and deadly. Until, armed with only tinkerblade and the magic of song, a boy would take on a man's challenge…and tread a treacherous path toward a magnificent destiny.