TruthSinger (Out of this World YA series)

Nathan loves music and is able to hear songs, songs that reveal the truth of whatever or whoever he meets. But he fears that his music and ultimately, Nathan himself, have played a very big role in his parents' separation. To add to his worries, Nathan has moved with his mother, to his Uncle Nevill's house, an eccentric, mysterious old man. He also has to deal with a school bully, and an unwanted, but insistent friend, Katie, who performs "magic."

Nathan and Katie are inadvertently caught in the summoning of Uncle Nevill by Myrrd, Wyndcaller of Angliocch, and find themselves in the middle of a power struggle between a boy king and a sorceress in a kingdom on a parallel world. In Angliocch, Nathan learns to embrace his gifts for music and hearing and uses them to play an instrumental role in helping the boy king ascend the throne. (less)