A Certain Ratio is a Post-punk band formed in 1977 in Manchester, England. While originally part of the punk rock movement, they soon added funk and dance elements to their sound. The band's name is taken from the lyrics of Brian Eno's song "The True Wheel" (from the album Taking Tiger Mountain , which in turn were taken from a quote from Hitler on the proportion of 'Jewish blood' that was required to determine whether someone was to be classified as 'Jewish'. There is some dispute as to whether the band were aware of the original meaning of the phrase. The group's longest serving members have been Martin Moscrop (guitar, trumpet) and Jeremy Kerr (bass, vocals). Another current member, Donald Johnson (drums, vocals), joined early to replace a drum machine. Three original members have left the band - singers Martha Tilson (left in 1982) and Simon Topping (left in 1983 for Quando Quango and, later, T-Coy), plus guitarist Peter Terrell, who