So Metallica play Glastonbury and the world didn’t end. I’ll be honest, I thought it might. Figured the hinky, something’s coming feeling, that there-but-not-quite-there squamous sensation that’s clearly heralding some sort of big bad ‘other’ would turn out to be linked to that. Not because all metal bands are Devil worshiping Satanists, far from it, more that the convergence of that much raw power (the biggest metal band in the world – trust me, they have power, with a capital POW) that clos...