I think that type of guitar is fine; it matches the color tones very well. Had you used the more interesting look of electric guitars or other some sort, I would have expected the rest of it to be more wild and bright. Perhaps it's just how I associate things, but other than the blockiness, it's fine.
Very nice! I like how your eye looks from him to the flowers and then back up again. At one time I really like the plain pattern in the background, but then others I think it might have needed a little more spice, such as other instruments or more depth even. Overall very good! Makes me want to draw now instead of play my game.
