Have you tried...following what is written on the paper?
Maybe there are no set answers. Maybe the piano just wants to spend a little more time with you.
Ah! I see. I guess I was too impatient. I initially typed "cats" but it didn't work :P
I finished the game and finally gave my rating! I love personal games that have a piece of the author in them. You have a knack for story-telling :)
Following you for more puzzle/story games in the future, so keep up the good work!