The harp of kings / Juliet Marillier.

Bard. Warrior. Rebel. Eighteen-year-old Liobhan is a powerful singer and an expert whistle player. Her brother has a voice to melt the hardest heart and is a rare talent on the harp. But Liobhan's burning ambition is to join the elite warrior band on Swan Island. While she and her brother are competing for places in this band, they are asked to go undercover as travelling minstrels. For Swan Island trains both warriors and spies. Their mission is to find and retrieve a precious harp, an ancient symbol of kingship. If the harp is not played at the upcoming coronation, the heir will not be accepted and the kingdom will be thrown into turmoil. Faced with plotting courtiers, secretive druids, an insightful storyteller and a boorish Crown Prince, Liobhan soon realises an Otherworld power may be meddling in the affairs of the realm. When ambition clashes with conscience, Liobhan must make a bold decision - and the consequences may break her heart.