Beavis and Butt-head, in their AC/DC and Metallica t-shirts, might best sum up the stereotypical metalhead in the popular Western imagination: a young white dude who likes headbanging and hates authority, found mostly in American cities or in Nordic countries with long, dark winters and plenty of old churches to burn. But South African photographer Paul Shiakallis’s series Leather Skins, Unchained Hearts provides a visual...