“Draw lines, young man,” Jean-Auguste-Dominique Ingres told the 22-year-old Edgar Degas in 1855, “and still more lines, both from life and from memory, and you will become a good artist.” When Degas was at the École des Beaux-Arts, that advice took the form of history painting. He relentlessly studied the work of El Greco, Caravaggio, and Botticelli. But he soon evolved, shifting to observations of contemporary life: milliners, laundresses, horses and their riders. By the late 1870s, Degas was venturing into new mediums—pastels, etching, and photography—which he used to capture nudes and dancers. This exhibition, timed to Impressionism’s 150th anniversary, focuses on Degas’s exploration of unusual media and his friendships with artists who favored technical experimentation. —Elena Clavarino