These are the books by Tim Bowler that are reviewed on this site:
Luke is in trouble. His father's dead, his mother would like to remarry, and he's in with the wrong sort at school. And that's just what's going on outside his head. Inside, there's a lot to master before his musical genius can really take off. Brilliant book!
Shipwrecked and alone amongst savages, Kit learns that the opposite of despair is hope.