hmmm
Well in my opinion, its good and its bad. The idea is there, but lacks... deffintion.
I only gave four stars because, I don't think its interactive enough, and it only plays a note for so long. Also a takes a moment for the note to acctually play.
Here is my advice. Talk experinced flash artists, talk to random flash artists, talk to musians, and ask thier advice, there is nothing wrong with that. I really like the idea, if you could get it so the notes on the piano keyboard on the screen, match with a typing keyboard, you would have an instant hit. I know it would instantly hit my favs because of my background in music, not only that but people like me who might need a piano music, but don't have an acctual piano would find this HELPFULL on so many levels. You could make others things like this, such as a synthasizer, that would be sweet.
Don't get discuraged. By critisims or bad reviews, keep working, your work shows promise. Send me a letter next time you put some work up.