Sorry I never commented on this, I've only had a chance to read a bit here and there but now I've caught up all the way. The idea behind the plot is really cool, and I like how many instruments, songs, and styles you include. It's obvious to me that you know quite a bit about music. What instruments do you yourself play, if I may ask? I absolutely love music, which makes this story really fun to read.
It's a little confusing, but I'm assuming that this all takes place in an alternate anime 'verse?
Very good writing overall, I couldn't find any glaring or recurring mistakes. Looking forward to more!