Banging on a geometric metal sculpture with my hand and recording the long reverberations with a vintage sony f-98 cardioid mic plugged into my iphone 6. I used various parts of the hand, the palm, fingernails, fist, and knuckles.
The microphone was placed inside a stainless steel metal box and placed in my shower. The shower rains onto the box and creates a rich, metallic resonance.