The cover of the program distributed to audience members at 9 Evenings shows a tangle of lines, a complex interweaving comprised of barely recognizable electronic symbols and scenographic notes. Like a palimpsest, the image consists of superimposed prints of each of the technical diagrams made for the event's ten performances. These drawings reappear within the program, where each performance is accorded a full-page description, half of which is devoted to an exquisite reproduction of the corresponding diagram. Produced by Bell Labs engineer Herb Schneider between the end of September and the beginning of October 1966, the diagrams elucidate the important role of technology in the performances of 9 Evenings, even while they include no legend or explanatory texts that would explicate the exact functioning of the technological devices suggested. Above all, the diagrams offer strong visual confirmation of the festival's principal subject, an unusual encounter between artists and engineers.