WHAT SHAPE might the narrative of modernism in the visual arts have assumed in the absence of New York’s Museum of Modern Art? Would we envision the history and evolution of modern art differently if we had not been guided for decades by the famous flowchart that MoMA director Alfred H. Barr Jr. prepared to explain the organization of his 1936 exhibition “Cubism and Abstract Art”? Here, for the first time, Barr crystallized MoMA’s paradigmatic vision of modernism as a progressive, formalist development across the European avant-gardes that could be traced along a dense network of intersecting