When I was 13, my family moved from Baltimore proper to the suburbs outside town. And in the first few months I lived out there, I made a weird regular habit of riding my bike a couple of miles to this one strip mall, which had the temerity to call itself a proper mall just because a few of its stores were inside. The mall had a half-decent arcade and a Hallmark store where nobody would bother me if I sat and read music magazines for 45 minutes at a time. Eventually, there was also a music store, where I got caught trying to shoplift an Ill Communication CD and got banned for life. And there was a K-Mart, which was entirely unremarkable except for one thing: The music section had a TV with a little push-button display, and it would let you cue up 20-second clips of music videos. I would stand there for way too long and press all the buttons and watch all the clips, even if I knew they were things that did not remotely interest me. This was the closest thing to YouTube I had. And one day, I pushed one of the buttons and saw four dreadlocked Brazilian guys, standing knee-deep in water, surrounded by sand dunes, covered head to toe in black mud, screaming at me. My mind was fucking blown. This was my introduction to Sepultura.

Watching Sepultura’s “Territory” video now, it’s a bit surprising to discover that the covered-in-mud part only happens like two thirds of the way through, and most of the video is about the Israeli/Palestinian conflict. But whoever was in charge of cuing up the video clips for K-Mart was on his fucking game. Because that shit seared its way into my brain and, in a lot of ways, cracked the entire universe of underground metal for me, the same way that Cannibal Corpse’s appearance in Ace Ventura did for a lot of other kids a few months later. The tribal caked-in-mud roaring was nothing Killing Joke hadn’t done a decade earlier, though I had no way of knowing that. Still: Holy shit. The image of those guys grabbed me the same way the image of the T-1000, half-exploded and teetering over a vat of molten steel, had grabbed me a year earlier, or the image of Tim Armstrong’s mohawk would a year later. My brother and I would just spend way too long in this K-Mart, hitting the Sepultura button over and over, gaping. And we bought the album, Chaos A.D., because of course we did. (The album turned 20 yesterday, by the way. That’s why I’m writing this.)

Chaos A.D. sounded exactly the way the 13-year-old me thought those four mud-wraiths should sound. It was the heaviest thing I’d ever heard. The first track, “Refuse/Resist,” starts with this amazing tribal drum refrain, clattering traps and juddering guitars playing call-and-response. (Drummer Igor Cavalera would bring that same swing when he’d play drums on M.I.A.’s “Born Free” years later.) Then, a few seconds later, when the main riff locked in, it was almost funky in the same way that Black Sabbath could sound almost funky — that almost-funk coexisting with world-obliterating ferocity. The choruses are massive and simple, often just one word shouted over and over at the exact moment where guitarist Andreas Kisser would break between riff-repetitions. The music could get fast at times, but mostly it was slow enough that you could let your brain disappear into it, that you could lock in right along with it.

I didn’t know it at the time, but Chaos A.D. was a transitional move for the band, who’d been around nearly a decade and who’d established themselves as global thrash-metal leading lights on their previous albums. This was their groove-metal move, the album where they slowed down and stretched out and concentrated on locking into a heavier beat. Pantera had done the same thing on the great Vulgar Display Of Power more than a year earlier, though I wouldn’t hear that album until later. And Chaos A.D. was full of weird little experimental touches, unorthodox decisions from a band that was trying to will itself out of any possible rut. “Amen” had opera singers howling. “Biotech Is Godzilla” had batshit Bush-created-AIDS-in-Brazil lyrics from Jello Biafra. The bonus track “The Hunt” was a cover of a song from the British crusty-hippie band New Model Army, and it had acoustic guitars all over it. None of this struck me as a break from metal orthodoxy at the time; I just accepted it all as part of the landscape of overall heaviness. The one song that did jump out was the elemental tribal acoustic-guitars-and-drums instrumental “Kaiowas,” and I usually fast-forwarded past that one, though now I think it’s among the heaviest songs on the album.

If you talk to full-time metalheads, almost nobody thinks Chaos A.D. is Sepultura’s best album. Instead, the cite thrash-era hallmarks Beneath The Remains and Arise, or Chaos A.D.‘s 1996 follow-up Roots, which has the odd distinction of being arguably the only truly great album to carry a distinct and obvious Korn influence. The general Chaos A.D. neglect boggles my mind. Those are fine albums, but Chaos A.D. is, for my money, the moment the band held it all together. I don’t think this is nostalgia talking. Favorite childhood albums don’t always hold up; this is something that became distressingly obvious the last time I tried to revisit Therapy?’s Troublegum. But I can’t think of a better introduction than Chaos A.D. to the vast metal underground that, before its release, I’d only vaguely been aware of. I’ve kept up with that underground, off and on, for the last two decades, and I’ve fallen in love with a lot of records and had my mind blown at a lot of shows. But I’ve never been more excited about its possibilities than I was the first time I saw those mud-covered guys on the K-Mart TV screen.