The Mamas and the Papas had a sound that helped define a portion of the 1960s. Their breezy folk classics had a bit of San Francisco psychedelia woven in, and, despite the sweet harmonies, there was also a noticeably dark feel to some of their more popular work. "California Dreamin'" and "Monday, Monday" both utilized enough minors to give them a spooky edge. Greatest Hits is an essential part of any audiophile's collection, especially if they don't have the original recordings that spawned the hits. "Dedicated to the One I Love" is almost ironic for its tenderness, considering the turmoil that rumbled through the band's interrelationships. While John and Michelle Phillips and Denny Doherty were all responsible for the success of the Mamas and the Papas, listening to this collection reveals that the late great Mama Cass was not only the heart but the soul of the band. Greatest Hits closes with her "Dream a Little Dream of Me," and serves as a touching tribute to Cass Elliot's talent. --Steve Gdula