Mama Cass knitting. Cass Elliot (born Ellen Naomi Cohen; September 19, 1941 – July 29, 1974), also known as Mama Cass, was an American singer and member of The Mamas & the Papas. After the group broke up, she released five solo albums. "If you truly dig what you are doing, if you lay it out that way, nobody can not respond. That's what rock and roll is; it's relentless."