Hey there, I agree completly with Sr. Ahurac about the intruments.
I would make the music box sound softer in the mix, as it stands too much compared to other intruments. I say this because taking into account that the real loudness of a music box is in fact very low, it feels weird to have it so loud on the mix.
Also, I could help you out with the instruments if you were interested. I play violin, so i could record it for you if you sent me the notes (just contact me in case you want to).
PS: Awesome track, very lovely :3