The Magicians of Caprona: Jones Wynne

Glorious new rejacket of a Diana Wynne Jones favourite, featuring Chrestomanci – now a book with extra bits!
The Dukedom of Caprona is a place where music is enchantment and spells are as slippery as spaghetti. The magical business is run by two families - the Montanas and the Petrocchis - and they are deadly rivals. So when all the spells start going wrong, they naturally blame each other.
Chrestomanci suspects an evil enchanter; others say it is a White Devil. Or maybe a different kind of magic is needed to save Caprona…