In the 1970s, Shelley wanted to extend her range, feeling she was not using all her capabilities as an actor. She told "The New York Times" in a 1979 interview that she had "months of the most intensive deep-water swimming — more than I’d ever been called upon to do in my life" when she played Rosalind in "As You Like It" at the 1972 Stratford Festival in Ontario. She received her first Tony Award nomination in 1975 for her performance as "Jane" in "Absurd Person Singular". Shelley won the 1979 Tony Award for Best Actress in a Play for her role as Mrs. Kendal in "The Elephant Man", and was nominated for the Tony Award as Featured Actress in a Play in 1987 for her performance in "Stepping Out" as "Maxine". In 1982 she won an Obie Award for her performance "Twelve Dreams". Shelley also began appearing in musicals in the late 1990s, with the revivals of "Show Boat" as Parthy and "Cabaret" as Fraulein Schneider in 1999.