Def Leppard are an English hard rock band from Sheffield who formed in 1977 as part of the New Wave of British Heavy Metal. Largely on the strength of their albums Pyromania and Hysteria Def Leppard became one of the top-selling rock bands of the 1980s. Music The music of Def Leppard is a mixture of hard rock, album-oriented rock (AOR), and heavy metal elements, and has been associated more with the glam metal movement of the 1980s than with the NWOBHM of the late 1970s, in large part