Def Leppard is a British band known for the songs Pour Some Sugar On Me, Hysteria and Photograph. The band released the albums High 'N' Dry, Pyromania, and Hysteria. Guitarist Phil Collen replaced founding member Pete Willis after two albums. Vivian Campbell stepped in to round out the group's twin-axe attack after Steve Clark died in 1991. The band has appeared in the documentary Def Leppard - Hysteria and the film The Freddie Mercury Tribute Concert.