There are often situations where you only need to practice a part of a song, so maybe you could add a practice mode where you can select a part of a song. That part could be looped until the player ends it by pressing escape. There could also be some useful stats on the screen while playing, which helps to see what you could improve at your playstyle.
I hope you like my idea and don't mind my grammar mistakes ;P
~SkaillZ
I hope you like my idea and don't mind my grammar mistakes ;P
~SkaillZ
(unrelated)