Answer
The answer is "Pippin." Cass Elliot, also known as Mama Cass, was an American singer best known as a member of the Mamas & the Papas. Aside from her music career, she also ventured into acting. Elliot appeared in several movies and television shows, including the Broadway musical "Pippin" in 1974. She played the role of Berthe, Charlemagne's grandmother, in the original Broadway production.