In the early ’80s, as the New Wave of British Heavy Metal was still ringing in headbangers’ ears, Sheffield, England’s Def Leppard bucked the trend by drizzling honey over hard rock. That audacious gambit sweetened a sound forged in the UK’s industrial heartlands and proved that power and pop were not mutually exclusive, paving the way for bands like Bon Jovi. Def Leppard formed in 1977 and soon settled on a core lineup of singer Joe Elliott, bassist Rick Savage, and drummer Rick Allen—just 15 when he joined. Guitarist Phil Collen would replace founding member Pete Willis after two albums and Vivian Campbell would step in to round out the group’s twin-axe attack after Steve Clark’s untimely death in 1991. Def Leppard made noise with its raucous 1980 debut, On Through the Night, but 1981’s High ‘N’ Dry proved that the band could write not just riffs but also hooks. The five members leaned into that strategy for 1983’s Pyromania, using producer Mutt Lange’s multi-track wizardry—gated drums, a hint of synth, and soaring vocal harmonies—to temper the guitars’ bite and Elliott’s shredded yell. It was 1987’s Lange-produced Hysteria, featuring sleekly melodic mega-hits “Animal” and “Pour Some Sugar On Me,” that confirmed Def Leppard’s status as the kings of pop-metal. In the early ’90s, as hard rock turned to grunge and grittier metal bands like Pantera, Def Leppard held onto their universal pop appeal, and it has served them well across decades of tours, studio albums, and live recordings. It’s a surprisingly simple yet ingenious idea: A little bit of sugar helps the metal go down.