This was interesting and very atmospheric. It's a fantasy book about Wolfgang's sister, Nannerl Mozart. It's actually based on the fantasy world that the Mozart siblings dreamed up while they were touring Europe called the Kingdom of Back. I didn't know anything about her, but she was also a child prodigy who was also a musical genius like her brother. Of course, women couldn't exactly make a living composing in the same way at that time, and the book does go into what that must have felt like for her.
The book wasn't action packed fantasy - it was more enchanting magical realism in a historical fiction setting. It's written in the first person, but doesn't have that "YA vibe" that a lot of YA books have. It's just kind of a slow, beautiful tale. I enjoyed the fantasy parts, but overall I can't say I loved this one since honestly I think I would have liked it more if it was just a historical novel. Still I liked it a lot!