This highly versatile actor has forever become identified as Martin Morgenstern, father of TV's "Rhoda" (Valerie Harper). But, if one examines Harold Gould's long career, on discovers that he has actually played a range of roles far beyond sitcoms, including leading man to Katharine Hepburn in "Mrs. Delafield Wants to Marry" (CBS, 1986) and a wonderfully manipulative Louis B. Mayer in "Moviola" (NBC, 1980).Tall, distinguished-looking, with white hair and a mustache, Gould actually began his career as an instructor and later a professor of acting on the university level. He made his