There will always be pseuds who’ll claim that, if you really think about it, silence is the heaviest sound of all. But it definitely isn’t, as you would soon discover if you tried to enjoy some silence at an Electric Wizard gig. Speaking of which, I once witnessed a burly metalhead vomiting during an Electric Wizard show, seemingly due to the overpowering, bowel-eviscerating bottom end the Dorset doom band were pumping out. That’s the bar we’re aiming for here. Heaviness should really be measured in terms of the intensity of the music itself, the atmosphere it generates and how quickly it liquefies your innards. Therein lies the essence of true heaviness: atmosphere, intent and an almost primitive physicality. And yet, heaviness is so easily confused with volume alone. Plenty of bands have claimed to be the loudest in existence, with Motörhead, Manowar and even My Bloody Valentine being particularly renowned for flagrant decibel abuse. And volume is incredibly important. There’s no point playing a riff that eerily evokes the end of the world if you have turned your amp down to avoid hurting people’s ears. But even cranked up into the overdriven red, none of the aforementioned bands would sound even remotely heavy placed next to New York no-wave icons Swans’ seminal 1984 album Cop. Musically pulverising and emotionally gruelling to an insane degree, it conjures a near-chewable atmosphere of tension, terror and torment. Similarly, if you have the stomach for heaviness in its most avant-garde and hostile form, listen to Japanese noise artist Merzbow’s 1994 masterpiece Venereology on headphones at high volume and try to string a sentence together afterwards. Ultimately, the most effective way of being heavy has long been via the medium of The Riff, as laid down by our lord and saviour Tony Iommi in 1969. As a result, the heaviest music of all time is likely to owe a debt to Black Sabbath but also be slower and darker and more malevolent. In metal circles, that all points back to the doom metal scene, its numerous offshoots and sub-strains, and wildly experimental bands such as Esoteric and Evoken (both of whom make music that sounds like the grinding of tectonic plates at the awakening of some horrifying Lovecraftian titan). Taking things even further, Sunn O))) have spent the last 22 years redefining what it means to be heavy, slowing doom metal down to an authentically earth-shaking, somnambulant drone. Experiencing the band in the flesh is (or rather, was) one of the most bruising, physical experiences available to the contemporary gig-goer, not to mention one of the most overtly psychedelic. At their subtly ingenious best (I recommend 2009’s Monoliths & Dimensions), Sunn O))) turn heaviness into an act of cathartic rapture, while also making it quite likely that audience members leave with empty bowels. In truth, though, the heaviest music of all time probably is best located in the ear of the beholder. It should be powerful, oppressive and capable of generating a profound sense of mortal dread. For me, that would be anything from The Greatest Showman. Or maybe Galway Girl. Suddenly, that Swans album seems featherweight and uplifting in comparison. The horror!