Def Leppard are an English rock band formed under the name Atomic Mass in 1977 in Sheffield as part of the new wave of British heavy metal. At the time of the band changing their name to Def Leppard, they consisted of bassist Rick Savage, lead singer Joe Elliott, guitarist Pete Willis and drummer Tony Kenning. The band currently consists of Savage and Elliott alongside drummer Rick Allen (since 1978) and guitarists Phil Collen (since 1982) and Vivian Campbell (since 1992).