Over the past seven years, Atlanta, Ga.’s Mastodon has perfected a brand of more-is-more heavy metal that bowls barriers and defies categorization in a genre that thrives on fine print and substrata. Prog, noise, doom, sludge, thrash or black metal: You’d be hard pressed to dig up an extreme music fan in any niche who couldn’t find something to latch onto in the band’s mass appeal meta-chug.

Mastodon albums get by without a strict guiding compass. Imagine the opening track from Blood Mountain, their latest album and a Relapse and Warner Brothers co-release (!): “The Wolf is Loose” revs with tangled drum rolls, opening up into a Bay Area gallop. A minute later, the track tenses into swiveling tech-metal, only to later unravel into a Clutch, desert stone groove. Mastodon has zero regard for the terms thrash, noise, doom, sludge or black metal, but they understand and embrace even the most diametric characteristics of all of them. Mastodon has dozens of high-volume influences alternately covered in sludge, crust or polish, and they let them all converge beneath a mega-loud surface.

Their sound unravels thick, textured and tall, like the sandpaper metal of Neurosis. Or it can let loose and get muddy, borrowing from Thin Lizzy’s cool womp or even Southern rock’s sunburnt lethargy. On some songs the band loses it, manic-style, headbanging to Anthrax’s crazed thrash; on others, they pick fights and challenge like early, pre-radio Genesis, fanning things out wide and getting consciously complex. In short, this is serious something-for-everybody fare, and it’s turning people on by the separate-but-equal truckload.

Meatheads love it for the tech side. To wit, the band’s musicianship is top-notch, gloriously exercised chops that don’t go unnoticed by the Revolver-reading mall lurkers or the Decibel-adoring noisenicks. It certainly doesn’t hurt that Mastodon has shared mega-national bills with the powerhouses of cred. Lamb of God? Check. Slayer? Check. Children of Bodom? Check. Tool? Check plus. Legit guest spots don’t shoo headbangers from the ball, either: Past albums have included appearances by Scott Kelly from Neurosis, Josh Homme from Queens of the Stone Age, and Neil Fallon of Clutch. These guys hang with metal’s board of directors on the daily.

But it’s not just ponytailed dudes in black Asunder tees and bongers in stone-washed denim jackets lining up at Mastodon’s altar. For better or worse, Mastodon enjoy the distinction of being the hipster set’s first bona fide metal crush. Before the Southern Lord affair and the Sabbath-eating Wolfma worship, it was 2002’s Remission that struck a meaty power-chord with the Pitchfork crowd. And, even then, it was the mixed bag of obscure influencesand the sheer power of the thingthat helped Mastodon find its mantle: Those moments of clean, psych-y creep leaping forth on tracks like “Ol’e Nessie” or the prevailing big, bombastic prog were duly noted.

Still, Remission was child’s play compared to the critically adored heaviness that would follow. 2004’s Leviathan and, of course, Blood Mountain were both hulks, tempos that boomeranged and arrangements that snaked around in scribbled schematics. Leviathan, a salty concept record about Moby Dick, was a monster in the magazines, and the New York Times-approved Blood Mountain, itself a concept album about fighting Cysquatches (one-eyed Sasquatches) and blood-sucking flies to the top a mountain, landed on a trillion year-end lists. Rolling Stone called it the ninth Best Album of 2006, and “Colony of Birchman” earned a Grammy nod. And there isn’t a Dylan in Mastodon.

So we all run in to pat them on the back, and everyonemetalheads, hipsters, folks that like musiclive happily after, together. Hooray! Lucky Mastodon, right?

Not so fast. They’re starting to win over the Wal-Mart parking lot set, the sight-seeing hipsters and the graying oldsters. They have bewitched editors at Terrorizer, Vice and The Times with just three albums. But what happens when there’s no one left to convince, when there’s nothing left to prove, when you’ve already pleased the whole world? I guess that’s the question waiting at the summit of Blood Mountain: How do you get higher when you’re already at the top?

Mastodon, Priestess and Caltrop play Cat’s Cradle Friday, Feb. 23 at 9 p.m. Tickets are $15-$17.