Viewed against the radical chaos of the 1960s, the minimalism of the American avant-garde presents a fascinating contrast. Artists of the time reduced their work to its essential elements—wood, steel, light. “It isn’t necessary for a work to have a lot of things to look at, to compare, to analyze one by one, to contemplate,” said Donald Judd. “The thing as a whole, its quality as a whole, is what is interesting.” Artists like Judd, Dan Flavin, John McCracken, Robert Ryman, and Fred Sandback never formed a group but built off each other, inadvertently creating a movement that redefined abstraction. In this exhibition at Zwirner, their work is placed side by side to emphasize the way color, or the lack of color, effects form and volume. Flavin’s rarely seen 1963 work, three fluorescent tubes, is one of many beauties in the show. —Maggie Turner