“From 1957, when Ms. Swope was invited by Jerome Robbins to shoot rehearsals of West Side Story, to 1994, when she shut down her Times Square studio and sold her archive, Ms. Swope produced hundreds of thousands of images of performers in action, capturing Gelsey Kirkland and Mikhail Baryshnikov in full flight, the cast of La Cage Aux Folles in full drag and John Travolta in full Saturday night fever.”