when the signal from the centroid "sum out" goes back into the centroid "channel 3", a feedback loop is created. (just like when you turn on a microphone next to it's output speaker and you get that shrill earsplitting sound) guys like hendrix and emerson figured out how to "play" this feedback at the brink of 'out of control' but still with expression.

this template plays four 12 measure chunks. first twelve measure = no feedback, second, third and fourth chunks each get a little more. the fourth starts to clip bad -- and if you left the level up on channel 3 much longer you might cause an audio engine fail or some other fail.