A small round cell of water in the dark, under colored lamps hung at different angles. Rings of needles on the rim feed it sound: flutes, organ pipes, a clarinet, a cello, singing bowls. The water answers by drawing mandalas of reflected light, and each lamp's angle picks out its own band of slopes.
Every puzzle shows a plate, a photograph of a pattern, and asks you to find the sound that makes the water draw it. Two flutes slightly out of tune make the mandala breathe in time with the beat you hear. Two loud notes can raise a third pattern that neither of them plays: the Tartini tone, made visible.
The flute, clarinet and cello voices are measured, partial by partial and breath by breath, from the University of Iowa Musical Instrument Samples (anechoic recordings, free for any use); only the measurements are published here.