The background is distracting to me. Something solid and not brown I believe would be a good choice.
It seems to catch a lot of light on top, bottom and the sides, and under the strings right near the bridge. Don't know if that is something that can be fixed when you take the picture or if it would have to be done with processing. I am a newbie too, so I don't really have any suggestions.
It is a really good upclose shot, and I like how it is cropped.
I would try & turn it on it side slightly & at a 45 degree angle, this will take some of the reflection out plus fill the screen & agree with ANDS some post sharpening.
Oh a plain background, I am hoping this was a test to see how it turned out.