“The job of the artist,” Jeff Koons has said, “is to make a gesture and really show people what their potential is.” Koons gestures toward art history and consumer culture. Born in 1955, at the end of the Baby Boom, he began his career in the late 1970s, riffing on inflatable toys. Then came conceptual work and his first sculptures, which included Michael Jackson and Bubbles (1988), a kitschy life-size gold-leaf statue of Jackson holding his pet chimpanzee. In the 1990s, Koons revived balloon art, but in mirror-polished stainless steel. “We’re balloons,” he said. “You take a breath and you inhale, it’s an optimism. You exhale, and it’s kind of a symbol of death.” Some consider Koons one of the foremost artists of our time. Others think he’s a sham. This exhibition spans five decades of his career, giving viewers a firm foundation on which to draw their own conclusions. —E.C.