From his debut in the 1860s up to his final works after 1900, the Paris Opera formed a focal point of Edgar Degas's paintings. He explored the theater's various spaces--auditorium and stage, private boxes, foyers, and dance studios--and painted those who frequented them: dancers, singers, orchestral musicians, audience members, and subscribers watching from the wings. This theater presented a microcosm of infinite possibilities, allowing him to...