Copper Urchin is a musical sculpture that is played by stroking its robust set of "sensory whiskers." Here the participant is able to experience the sensation of creating musical sound while their hands are enveloped in a responsive and malleable medium. The whiskers are metal wires that when deflected cause a musical note to play. An amber light at the base of each sensor illuminates to indicate that it has been deflected to a sufficient degree and remains lit for the duration of the participant's gesture.