“A painting requires a little mystery, some vagueness, some fantasy,” said the French Impressionist Edgar Degas (1834–1917). “When you always make your meaning perfectly plain you end up boring people.” Degas trained under a classical painter in Paris, and his style was refined. Yet a haunting ephemerality and ambiguity set his work apart. His renderings of ballet dancers, for instance, did not idealize them, but saw them as real women, both sensual and soiled, luminous in the theater but financially impoverished and preyed upon by rich men. In this exhibition, 76 Degas works from MASP’s collection, which haven’t been seen in 14 years, are displayed alongside new photographs of the works—black-and-white images by Sofia Borges—creating a dialogue across a century. —E.C.