Half-pipe plate variations, laid in the traditional overlapping convex, concave, convex, concave manner; each mechanically free of its neighbours, attached and touching at only at one point - to an underlying stringer, that attached to the soundboard roof underlay.
Quite a few man hours goes into the arrangement of the variety of shapes, sizes, materials and attachment points, to lend a pleasing visual, as well as aural pastiche, while retaining its raison d'etre, ie: keeping the rain off.
Most effective during hailstorms.-- FlyingToaster, Dec 24 2016 this could be worse than Chinese water torture. Amazing-- theircompetitor, Dec 24 2016 Because of this idea relying on weather, I think you are going to need help from a computer cluster for a pleasing auditory whimsy.
Timing/tempo might be a issue so a capacitance, of some sort, would have to be included.-- wjt, Dec 24 2016 random, halfbakery