Really Cool
Really Cool, nice idea, didn't try to submit anything to the portal so I don't know how well that works, anyway, here's what you would need to do to get a 10:
There are several instances where a measure is not four bars, I found several that are 5 or 6 bars long, this really throws off composing music, please fix all bars to be 4 measures long!
The play-back speed, instead of being a number, would be more helpful if it were a musical bpm.
It would be nice to have the ability to create longer songs, implementing a scroll-bar would be nice in that respect.
Lastly, and this is when you'd pretty much be generating a full-blown synthesizer, it would be nice to be able to modify pitch data for a specific sound, and a volume adjustment for each sound as well.
Anyway, I think this is a really cool submission and it works pretty good. Making the above changes would make this flash absolutely brilliant.