Eh...this other thing is only important if you plan on making it much more realistic (apart from Jr.Who's advice to throw in some anti-aliasing, which I agree with), is to replace those sheet-music textures...I'm not sure if it's just the image I'm looking at that makes them look fuzzy and low-resolution, but I think they could do with sharper images.

https://images.google.com/images?hl=en&q=sheet+music