Physically situated public art poses significant challenges for the design and realization of interactive, electronic sound works. Consideration of diverse audiences, environmental sensitivity, exhibition conditions, and logistics must guide the artwork. We describe our work in this area, using a recently installed public piece, Transition Soundings, as a case study that reveals a specialized interface and open-ended approach to interactive music making. This case study serves as a vehicle for examination of the real world challenges posed by public art and its outcomes.