Kinetic sculpture

Alexander Calder's mobiles made motion a sculptural medium, and wind-driven work has been a public art staple since: it animates a plaza without a power bill. The commissioning reality, though, is mechanical: moving parts wear, bearings seize, motors fail. A kinetic commission is a commitment to mechanical maintenance, and the contract should say who performs it and what the work is allowed to look like when it's stopped. A stilled kinetic piece reads as broken in a way no static sculpture ever does.