Out with stuffy corsets, in with hot pants and mini skirts. A major exhibition on designer Mary Quant, who transformed British fashion in the Swinging Sixties, uses 120 items of clothing—plus accessories, cosmetics, sketches, and photographs—to illuminate London’s visionary of mod. “The whole point of fashion,” Quant famously remarked, “is to make fashionable clothes available to everyone.” —J.V.