The hard gone soft, the raw cooked: This is the Claes Oldenburg we know and love, the Oldenburg of Soft Toilet, 1966, and Giant BLT (Bacon, Lettuce and Tomato Sandwich), 1963—shiny and tasty American wares fallen victim to gravity and deflation. But beginning in 1976, the artist’s collaborations with the late Coosje van Bruggen seemed to reverse course, stiffening into polished monumentality. While the Guggenheim and the National Gallery’s shared 1995 Oldenburg retrospective struggled to tie together these bodies of work, this survey leaves things largely bifurcated. Its first half, which includes rarely seen films, focuses on Oldenburg’s protean investigations of production, from The Store to soft sculptures to mid-’60s Happenings. Its second features his and van Bruggen’s little-known group of Brobdingnagian musical instruments, quite another take on collaboration and performance.