Petaloom is a mallet percussion instrument with bars of aluminum. Instruments like this benefit greatly when each bar has a tubular air-resonator tuned the bar pitch, and for this instrument I used an unusual resonator arrangement. The resonators are tubes of thin-wall plastic, fairly soft and flexible. They are attached directly to the bars, parallel to them. You’d expect the attachment of the resonator directly to the bar would kill the bar’s vibration, but by careful positioning and balancing of various factors I got things to where dampening is fairly minor: the tone remains clear but the sustain is reduced. Direct contact between the bar and the flexible resonator tube means that the vibration of the bar drives the air in the resonator quite effectively. Between the partial damping, the shorter sustain, and the rich air resonance, the resulting tone has a warm, almost woody quality.