@MultipleChoice: I really like your tutorial with the synthesizer. I'm making a music game and I'm having similar trouble like the question you were asking.
I'm using a gamepad, and basically my game is you hit the A button and a note or a chord plays. Right now I have it set so that when you release the A button it just stops immediately, which isn't very musicy. I want the sound to fade as it would in real life on a real instrument. I tried it with the gain effect and it sounds pretty good but then I can't play the same sound immediately after it. One A button press/release will work, but the next won't.
Any ideas on how to make this happen?