Nice idea and it's looking good. I second Tyson on the crits though...
I'd also suggest really over exaggerating the motion. The transition into the scared jump is 1 frame (not really a transition at all) but if you really exaggerate the anticipation and then the action (ie do as Tyson says and have him shake around a little) you could get away with that one frame transition.
I'd also spice up the action of the notes (and you might want to flip the anim around too as the notes are back to front

)