The waterphone is an inharmonic acoustic percussion instrument consisting of a stainless steel resonator bowl or pan with a cylindrical neck and bronze rods of different lengths and diameters around the rim of the bowl. It was invented in the late sixties by Richard A. Waters who was influenced by the Tibetan drum. When a small amount of water is placed in the tube it produces a sound sometimes compared to the song of whales and other cetaceans.
Here's what it sounds like:
Via Curiosites de Titam