Al Green, from the cover of his Greatest Hits album, first released in 1975. Courtesy of the artist hide caption

itoggle caption Courtesy of the artist

Paul Williams, Eddie Kendricks, and David Ruffin of the Temptations, in 1965. Hulton Archive/Getty Images hide caption

itoggle caption Hulton Archive/Getty Images

Mama Cass Elliot with her Mamas and the Papas bandmates John Phillips and Denny Doherty in 1966. Express/Getty Images hide caption

itoggle caption Express/Getty Images