Do not press play on the video. Don’t do it. It will hurt. This is some sort of circuit bent synth that can create chaotic music. While the folks at Make suggest its fun at parties, I beg to differ.
The Benjolin is a ‘noise box’ that is ‘bent by design’, meaning that it always has a definite amount of unpredictability while it is still intuitive to play. The Benjolin features two eighteen-octave range voltage controlled oscillators that drive a ‘rungler’ circuit, circuitry that in essence uses a special interference technique feeding back into the oscillators to force them into wild chaotic behaviour.
You can learn how to make your own here. If you do, please tell us so we can leave your town.