Gorgeous
Absolutely gorgeous piece, I really love how you handled the lighting, it really adds to the overall feel of the picture, as well as how you took the time to include a background (Even if it's not nearly as detailed as the foreground), as many artists seem to pass over now-a-days.
As for improvements, the only real gripe I have, is that she is rather really tiny, or that violin is freaking massive. Or it could just be the way I'm looking at the picture... I'm so out of practice as an artist it's not even funny.
Either way, gorgeous picture, it's my pick for "Art of the Week"! Congratz and keep up the awesome work!