This is another demonstration of tiction. Here you can see a few circuits getting created, connected together, broken apart, and destroyed, all while firing off MIDI note messages.
This example also highlights a couple problems: with all the nodes moving around, it's hard to chase one down with your mouse without stopping the motion. So I'll need to figure out a way of either cycling through the nodes with the keyboard, or make a command that sucks a node under the mouse pointer.
The second problem is that the note timing is currently driven by Processing's draw() function - so varying frame rates mean slowdowns/speedups in the sequence. The message scheduling will have to be moved off into a separate thread.