This was fun. Was a nice Nostalgia Trip back to playing with Flash Music mixers in Highschool. Really dig the Sci-Fi Twist. Just need to add some more plants and other Sci-Fi components to allow for more tones and sounds and I think you could run with this. Maybe even make the beats you mix sharable and people could creating something and link it to Facebook.
This was featured in the first episode of my Ludum Dare 38 showcase. So some of the footage is from a couple other games as well. As a heads up to other viewers.