It’s hardly worth reiterating the connection between Heavy Metal and dark, often upsetting imagery. The artwork used to push records and merchandise has always been the first talking point in any critique of extreme music and this has both served and damaged its legitimacy in the larger public eye. While the moral outrage has all but fizzled out since the Satanic Panic of the 1980s and contemporary bands now enjoy the kind of immunity not afforded to their peacockish forebears, the recent controversy in the USA regarding the Confederate flag has forced a previously unchallenged theme in Metal to surface,…