Fun's in fashion when Fred Astaire and Ginger Rogers (plus Irene Dunne and Randolph Scott) enter the ultrachic Parisian world of high fashion in "Roberta." The third Astaire/Rogers film is a silky adaptation of the 1933 Broadway hit (whose original cast included Bob Hope, Sydney Greenstreet and Fred MacMurray). It features a jaunty romantic plot, fabulous sets (the three-level salon set required the world's largest camera crane), memorable music (including Jerome Kern and Otto Harbach's "Smoke Gets In Your Eyes") and above all, incomparable dance magic to match the score. "The most pleasant moments in 'Roberta'," Time reported, "arrive when Astaire and Rogers turn the story upside down and dance on it." Astaire may sing "I Won't Dance." But his feet betray him.