I am not too sure about the composition and how the hand is set against the guitar.
Doesn't look like anyone is actually playing that guitar. Wonder if you were trying to portray Hendrix and the 60's here. The colours and the left hand do suggest that. But I find everything else a bit out of place.
This just doen't work for me. Back ground too busy. Maybe show more of the person's arm/hand. Or shot more from the side of person instead of from back