Abstract art means many things. It is not as simple as a room full of gestural paintings, almost indistinguishable from one another. It varies beyond the use of linear shapes and pure geometry.
This was a year whose high points included Joan Jonas’s luminous survey, the extravaganza “PST ART,” and the 24-karat beauty of a show “Siena: The Rise of Painting, 1300-1350.” ...