Growing up in '60s and '70s England, the members of Def Leppard were immersed in the sterling sounds of the British rock titans of the day—which you can hear in their propensity for colossal riffs (Zeppelin), clever pop hooks (Bowie), and stacked backing vocals (Queen). But they were also exposed to underappreciated glam troupes like Slade, The Sweet, and Mott the Hoople—bands that combined a flashy image with stomping rock power. They also fused those groups' infectious songwriting with the hefty twin-guitar harmonies of Thin Lizzy and Judas Priest, KISS' bombast, Van Halen's six-string pyrotechnics, and Boston's widescreen production to create their gleaming pop-metal sound.