Good try, but not great implementation
Firstly, all of the notes are a helf-step too high. Secondly, the high "C#" (which is really a D) is the same note as the low "C#".
Other than that, it looks good-great graphics. The different instruments is a good idea, as is the playback.
Try fixing the glitches mentioned above, and this could be really good. Perhaps try to allow for shorter and longer notes-eigths, quarters, half notes, etc. I'm sure this stuff is hard to do, but if you have a variable that stores how long a key is being pressed, then once it is released it can be written on the music staff...or something like that.
Good effort; keep trying :)
I voted 3.