Yes, the classic concept behind the HP200A. Check out the trick light bulb.
Sadly, as best I can tell, the bulb doesn't do what it's supposed to do (increase resistance with amplitude) so it's no better than a 75R resistor, and the oscillation eventually dies out. Maybe EC will improve the light bulb model... Probably not high on the list of priorities, though.
"Shake" the canvas to inject noise and get it started.
