A clever alternate spelling of their namesake and bass player, this metal outfit forcefully demonstrates that the greatest metal recordings of all time owe much of their heaviness to Geezer Butler. G//Z/R even appears to target Tony Iommi -- whose contribution to Black Sabbath is often described in more significant terms than that of Butler -- on the vicious "Giving Up the Ghost." With more than enough power to eclipse any sans-Butler Black Sabbath or Iommi project, this 1995 release proves its creative point. Engineer Paul Northfield deserves special credit for fusing the punishing sounds of guitarist Pedro Howse and drummer Deen Castronovo with Butler's famous low end. Fear Factory vocalist Burton C. Bell's holler wears a little thin at times, but he never crowds G//Z/R's super-heavy riffs. With its historic membership and rock-solid execution, Plastic Planet reaches rarely achieved metal heights.