Searching for a book...

[ChrisKash]

I read a book when I was younger that I'm searching for now. I can only barely recall details... it's about a boy growing up who has magic. Key plot points I think I recall:

• He's born on a battlefield/was on a battlefield and kills everyone?
• He has incredible power but it's linked to a demon inside him (I think...)
• His home town/city is destroyed (to get him?)
• He is an amazing musician and that's what he does as a living
• He is caught and capsizes a boat to kill his captors who drown cause of their armor... think he dies as well
• There is a woman who tries to kill a king/emperor who killed her sister

I know it's not much to go on and I have always been a prolific reader so I'm hoping I haven't mixed in aspects of other books... It's not Lion of Macedon though it shares similarities.

I've been looking for this book off and on for years now, never came across it again!

Thanks for your time and help.

Chris