Deep Purple is an English rock band. Following a lineup change in 1970 where singer Ian Gillan and bassist Roger Glover replaced Rod Evans and Nick Simper, the band released the albums Deep Purple In Rock and Machine Head, featuring Smoke On The Water. The band's songs include Knocking at Your Back Door, Perfect Strangers, and Woman from Tokyo. In the mid-1970s, David Coverdale replaced Gillan, Glenn Hughes replaced Glover, and Tommy Bolin replaced guitarist Ritchie Blackmore. Deep Purple has been featured in documentaries and films including Deep Purple - Machine Head and Deep Purple With Orchestra: Live At Montreux 2011.