Iron Maiden are a British heavy metal band formed in 1975 by bassist Steve Harris. After several lineup changes prior to their recording career, they settled on Harris, vocalist Paul Di'Anno, guitarist Dave Murray and drummer Doug Sampson. The band released an EP as a four-piece, before hiring guitarist Dennis Stratton in 1979. Doug Sampson was dismissed from the band as he was unable to cope with the touring schedule and, at the suggestion of Stratton, replaced by Clive Burr, with whom the band recorded their self-titled debut album in 1980. Later that year, Stratton was replaced by guitarist Adrian Smith, due to musical and personal differences brought about by choosing not to travel with the band when supporting Kiss on the European leg of their Unmasked Tour.