The literal and the whimsical meet in The X and Its Tails. Long before the minimalists talked about lifting sculpture off its pedestal, the pragmatist Alexander Calder made some sculptures hover in the air and other sculptures squat on the ground.
Son and grandson of Philadelphia sculptors, Calder had been trained as an engineer, but he drew the art world's attention in the 1920s with an animated circus built from wire figures and wooden toys.
Prompted by Mondrian's drastically simplified paintings, Calder began to experiment with free-standing abstract shapes and primary colors. Jean Arp gave them their name of "stabiles." Next, Calder cut leaflike shapes, reminiscent of Miro, from sheet metal, attached them to rods and suspended them from the celling. Marcel Duchamp obliged and called them "mobiles."