For this app, polygons are drawn and influence the sin oscillator associated with them based on the number of points that each polygon has. The playhead goes from left to right and once it goes over a vertex of one of the polygons, it plays the sin osc associated with that poly. I had trouble with the clipping of sound, when it is switched on.
This is a drawing application that allows the user to create sound by drawing gradients and adjusting the speed of the playhead.