In the beginning, there was Led Zeppelin ? and Black Sabbath, and Deep Purple, the progenitors of British heavy metal, a musical form that wildly expanded the terrain of rock in the early Seventies. And as that decade progressed, it began to mutate, as Judas Priest fused heavy metal's intensity and dark emotion with unbridled theatricality and the power of twin guitars. The New Wave of British Heavy Metal was underway. Five young men from Sheffield ? some of them still in school ? took that new sound and infused it with large doses of the glam they'd grown up on ? T. Rex, Queen, Davie Bowie ? and blazed a trail into the Eighties, leading NWOBHM into the new era of MTV. Taking the name Def Leppard, they brought unprecedented energy and innovation to every song, to every show, then partnering with legendary producer Mutt Lange to become heavy metal's apostles to top 40 radio ? delivering an astonishing string of hit singles and multi-platinum albums while setting new standards for arena rock. They're still rocking the world today, a dozen albums in, touring the world and never resting on their laurels. Heavy metal, NWOBHM, hair metal have all come and gone ? but Def Leppard remain. AUTHOR: Scott Robinson is a writer, musician, technologist, and lifelong fan of classic rock. He was a music critic for the Louisville Courier-Journal for 20 years, and has been published in Rolling Stone and the Wall Street Journal. His previous books include The Beatles Guide to Love & Sex, All We Are Saying: The Political Beatles, and the Rock Candy series. He lives in Indiana, USA