Def Leppard is a British rock band formed in 1977 in Sheffield, England. They are known for their catchy melodies and polished production, which helped define the sound of 1980s hard rock. The band's lineup includes lead vocalist Joe Elliott, guitarist Phil Collen, and drummer Rick Allen, who is famous for playing with one arm after a car accident. The band gained international fame with their albums, particularly Pyromania (1983) and Hysteria (1987), which produced hit singles like "Pour Some Sugar on Me" and "Photograph." Def Leppard has sold over 100 million records worldwide, making them one of the best-selling rock bands in history.