Before his Ben-Day dots pelted the art world, the young Roy Lichtenstein experimented with different styles, especially satire. From 1948, when he was 25, to 1960, he tweaked popular culture, drawing on fairy tales, caricatures, folk and children’s art. He also explored various forms of Americana, looking to 19th-century representations of Native Americans and cowboys. He even toyed with abstraction. This fascinating show is a portrait of the artist in search of his voice. —E.C.