The strumming is accomplished by spinning fans and jiggling wires (cords?), with, as far as I can tell, no digital control or manipulation of the sound.
This definitely passes the “inappropriate touch screen” test!
Now, I’m not especially fond of the hazy, lazy, ambient sound produced. And there doesn’t seem to be much way to influence the sounds—you get whatever you get.
OK– I laughed at the junction box, but honestly, the tangle of wires is ugly (and probably a safety hazard).
But this is hardly a useful technique, or likely to entertain for more than a few minutes.