Mitchell-Innes & Nash: Postwar classics combine in this booth with more jarring contemporary fare in a vibrant mix with an electric charge. Among the classics is the jewel-like 1949 Jackson Pollock drip painting “Number 21.” Composed of oil and enamel on paper mounted on board and not seen in public since 1979, the gallery has it pegged at $25 million. Facing the exquisite Pollock, with its underlying grid of black dots, is Pope. L’s much larger and noisier abstraction “Gold People Dick the Mist,” from 2015-16. You can almost hear the crackling dialogue between the paintings. Also on display is Tom Wesselmann’s 1964 Pop art wall relief “Still life #53,” made of painted molded plastic and featuring an old-fashioned radio, as well as Nancy Graves’s decidedly minimal 1971 floor-sited work “Scatter Piece,” which resembles in part the bone fragments from an archaeological dig.