Dissecting Fleetwood Mac's fiery fusion of frisky rock and breezy pop makes for a fascinating survey of '50s icons, '60s mavericks, and '70s superstars. They find romance in The Everly Brothers' smooth harmonies and The Mamas & The Papas' soft California pop, power through heartbreak with the swinging rock 'n' roll of Buddy Holly, and cope with regret as pointedly and poignantly as Dolly Parton.