“Picasso was trying to push his mortality at bay throughout his life, while Calder, on the other hand, was fascinated by the vastness of the world, looking outside himself.” This comment comes from Alexander Calder’s grandson, Alexander S. C. Rower, who teamed up with Pablo Picasso’s grandson, Bernard Ruiz-Picasso, to curate a small exhibition in 2016, one that explored the way each artist approached empty space—the void! The director of the Musée Picasso-Paris saw the New York show and asked the grandsons for more. This much larger exhibition includes 120 paintings, sculptures, and archival photographs. Who said success doesn’t happen in a vacuum? —J.V.