The Mamas and the Papas are a musical group from the 1960s. They sang folk songs, are attributed to be part of the folk-rock movement of the mid to late 60s. The early members were John and Michelle Phillips (married) and Denny Doherty and Cass Elliot. Cass was called Mama Cass. you might have heard "Dedicated to the One I love, California Dreamin".
Cass Elliot died prematurely of a heart attack due to her weight/size. Some of the band members now have famous children - Mackenzie Phillips (an actress who struggled with drugs like her father), Chyna Phillips (of Wilson Phillips band fame).