For 9 Evenings: Theatre & Engineering, Rauschenberg choreographed a performance called Open Score. He asked engineer Pete Kaminski to implant an FM transmitter into the handle of a tennis racquet used in a match between artist Frank Stella and his tennis instructor Mimi Kanarek. Every time the ball made contact with the racquet, a sound was transmitted and a signal shut off a section of lights, until the space was in complete darkness. By the end of the performance, an infrared television system revealed to the audience a cast of nearly 500 performers gathered on stage.