Nighttime at the Philadelphia Museum of Art, featuring the work of Arshile Gorky through Jan. 10, 2010. From the museum’s Web site:  Arshile Gorky: A Retrospective celebrates the extraordinary life and work of Arshile Gorky (about 1902–1948), a seminal figure in the movement toward abstraction that transformed American art. This exhibition, which includes about 178 works of art, surveys Gorky’s entire career from the early 1920s until his death by suicide in 1948. The retrospective includes paintings, sculpture, prints, and drawings — some of which are being shown for the first time — and reveals Gorky’s development as an artist and the evolution of his singular visual vocabulary and mature painting style.