One of Patti LuPone's twin older brothers, Robert LuPone performed with siblings William and Patti as The LuPone Trio during the 1960s. He made his Broadway debut in "Minnie's Boys" in 1970 and later acted onstage in "Jesus Christ Superstar" (1971), as well as appearing in the 1973 film version. His role as the choreographer-director Zach in the original Broadway production of "A Chorus Line" (1975) earned him a Tony nomination as Featured Actor in a Musical, and his subsequent Broadway parts included the Dauphin in a revival of George Bernard Shaw's "Saint Joan" (1977) and David in "Late Night Comic" (1987). Off-Broadway he appeared as John Lennon (and other parts) in "Lennon" (1982), and he acted in Joseph Abady's world premiere of "On the Waterfront" at the Cleveland Playhouse in 1989. Like many NYC-based performers, LuPone amassed extensive credits in daytime serials but he is perhaps best recalled for his Emmy-nominated portrayal of relentless extortionist Zach Grayson on ABC's "All My Children" from 1984 to 1985 and as Roger Thorpe's sleazy attorney Leo Flynn on "Guiding Light," a part he's essayed on and off since 1991.