At 21, Aaron Turner -- founder, owner, and, until recently, the sole employee of Hydrahead Records -- is barely old enough to be admitted to the clubs where his bands perform (at least in Boston, where all-ages shows are hard to come by these days). In fact, the seeds of Hydrahead were sown before Turner was old enough to vote -- when, from his bedroom in New Mexico, at the age of 17, he formed a mail-order distribution company specializing in hard-to-find punk-rock records. Before he was old enough to drink, he was negotiating with major-label reps: in 1997, Walter Yetnikoff's label Velvel signed Miltown, a band who'd put out their first single with Hydrahead, and who subsequently released an EP with Turner's label even after they'd moved to the big leagues (the joke was on Yetnikoff when Miltown broke up without releasing anything further). Now, from an apartment in the sketchy part of Mission Hill, this art student/musician (he's at the School of the Museum of Fine Arts and fronts Isis, a tinnitus-inducing noise/metal swarm) has put Hydrahead at the forefront of an emerging renaissance in the loud arts. He's already helped retool the aesthetics of metal and hardcore from the underground up. And he's just getting started."I grew up in New Mexico, and there wasn't a whole lot as far as youth culture is concerned," says Turner, who moved to Boston and put out his first release in 1995. "Especially when I started to get interested in straight-edge and wasn't doing drugs anymore, there was really nothing for me to do. So that was like a big reason for me, I suppose, to become really productive. Also, I've never been a really social person. So there's not a lot of time taken up by my social life. And music has always been a very very big part of my life. I guess just a combination of those factors is why everything got started so early."

Turner has that rare, intuitive gift that for lack of another term I'll call vision. He has the underground equivalent of what major-label A&R reps call a "great ear," and with his painter's eye he's overseen exquisite packaging and artwork that dramatizes the music's narrative drive -- namely, the creep of heavy metal out of the Dark Ages and into an Enlightenment. Friends describe him as unassuming; in person he's tall, lanky, easy-going, even subdued, but deliberate and clearly focused. There is no boastful edge in his voice when he says, "I really don't feel that there is any competition for Hydrahead in this area."

Indeed, there isn't. Although the label's releases are regularly selling between 3000 and 5000 copies each -- highly respectable for a mid-size indie label, and almost unheard of for a three-year-old, one-man operation -- Hydrahead has kept a low profile in Boston and isn't readily identified as a local label. Through mail order it's sold discs as far away as Russia, Malaysia, and Japan; about half the inventory is sold outside New England. And though most of the Hydrahead roster is from the Northeast, Turner has released singles by an impressive list of nationally renowned heavy hitters: Brutal Truth, Today Is the Day, Eyehategod, Converge, Anal Cunt, Coalesce, and the Dillinger Escape Plan.