The sideways music scroll feels very uncomfortable for me. I guess I'm used to guitar hero. I beat both levels by spamming the strum bar (turns out you can win by holding all three buttons and spamming strum). I'm not sure what this has to do with grinding. You are using more than 2 colors with your text, next time turn off anti-aliasing. The intro text-scroll is also a little too fast to read at that size text.
Cool start.