Deep Purple are an English hard rock band from Hertford, Hertfordshire. Originally known as Roundabout, the group formed in March 1968 featuring vocalist Rod Evans, guitarist Ritchie Blackmore, bassist Nick Simper, drummer Ian Paice and keyboardist Jon Lord. This first lineup of the band, known as Mark I, released three albums within the space of a year – Shades of Deep Purple, The Book of Taliesyn and Deep Purple – before Evans and Simper were fired from the band at the request of Blackmore and Lord. Mark II of Deep Purple saw Ian Gillan and Roger Glover replace Evans and Simper, respectively, in the summer of 1969. This lineup of the band has since been identified as their most successful, with their next four albums reaching the top four of the UK Albums Chart, including number-one albums Fireball and Machine Head.
After the release of seventh studio album Who Do We Think We Are in early 1973, Gillan left the group due to creative differences with Blackmore, and was followed shortly by Glover. Deep Purple, Mark III were formed later in the year with the addition of vocalist David Coverdale and bassist and vocalist Glenn Hughes. This lineup released two studio albums – Burn and Stormbringer, both in 1974 – before founding member Blackmore left the band, reportedly due to the new influences of funk rock presented by Coverdale and Hughes. Mark IV of the band, featuring Tommy Bolin in place of Blackmore, released their only album Come Taste the Band in 1975, before breaking up the following year.