AC/DC are an Australian hard rock band, formed in Sydney in 1973 by brothers Malcolm and Angus Young. A hard rock/blues rock band, they have also been considered a heavy metal band, although they have always dubbed their music simply rock and roll. AC/DC underwent several line-up changes before releasing their first album, High Voltage, in 1975. Membership subsequently stabilised until bassist Mark Evans was replaced by Cliff Williams in 1977 for the album Powerage. Within months of recording the album Highway to Hell, lead singer and co-songwriter Bon Scott died on 19 February 1980 after a night of heavy alcohol consumption. The group considered disbanding, but buoyed by support from Scott's parents, decided to continue and set about finding a new vocalist. Ex-Geordie singer Brian Johnson was auditioned and selected to replace Scott. Later that year, the band released the new album, Back in Black, which was made as a tribute to Bon Scott. The album launched them to new heights of success and became their all-time best-seller.