The hush

"Chester has taken to the road, traveling from village to village desperately searching for his father, who has disappeared. One night while fiddling to earn a few coins, he accidentally connects to the Song-the music that fuels every aspect of the world, and that it's illegal for him to interact with. He's caught and sentenced to death for his crime. Only a licensed Songshaper can bend music to his will. But someone in the crowd-a member of the infamous Nightfall Gang-stages a daring rescue and whisks Chester into the Hush, a shadowy nightmare mirror-world where Music can be deadly and Echoes can kill. Susanna, the Captain of the Nightfall Gang has been watching Chester. She needs him to pull off an elaborate plan that will take down the governing body that keeps her an outlaw and made her the fragment she is. Susanna needs him to exact her revenge, even if he dies doing it. Combining complex stakes, shifting loyalties, nods to fairy tales, and a Western feel, The Hush is a lush and exhilarating fantasy perfect for fans of Catherine Fisher's Incarceron and Paolo Bacigalupi's Ship Breaker"--
"In his quest to find his father, a fiddler joins an outlaw gang as they launch a plan to dismantle the musical system that controls their world"--