As the owner of the trendsetting local label Hydrahead, and the frontman of Boston indie-metal behemoths Isis, Aaron Turner is a point man on the heavier side of the Boston underground-rock scene. So it’s no surprise that he’s rounded up some of the biggest guns in town for his latest band, the mind-expanding ambient/doom experiment Old Man Gloom. Originally conceived during a short visit Turner made to his home state of New Mexico in the summer of ’99, the group recorded their first disc, last year’s Meditations in B (Tortuga), as a duo with Turner on guitar and vocals and Santos Montano on drums. Soon after, OMG expanded to include Converge bassist Nate Newton on guitar and vocals, Cave In bassist Caleb Scofield on bass and vocals, and Luke Scarola on sampler.

“It’s a pretty loose organization,” explains Turner when we meet up at the Brown Sugar Café, in the Fenway. “We just asked a few of our friends if they wanted to play with us, in a very noncommittal sense. We knew that Nate really liked playing guitar, and he didn’t have the opportunity to do that in Converge. Plus, we really liked his voice. We knew Caleb was a great bass player, and he wasn’t getting to play heavy shit in Cave In anymore. I think the personality of the new OMG records is largely due to Nate and Caleb and Luke’s involvement.”

He’s talking about the band’s two new discs, Seminar II: The Holy Rites of Primitivism Regressionism and Seminar III: Zozobra, which were released simultaneously on Tortuga last month. Together with Meditations in B, they form an unnerving trilogy of Sabbath-style doom punctuated by the warring screams of the group’s three singers and plenty of minimalist background noise. Seminar II is the most expansive of the bunch; Seminar III consists entirely of the ebb-and-flow half-hour title track — like a miniature version of Sleep’s ’99 dirge-rock landmark, Jerusalem (The Music Cartel). Sure, several of Turner’s riffs could easily be Isis outtakes, but that group’s festering drone has been largely replaced with a heavier cut-and-paste sensibility.

“Initially, OMG was the antithesis of Isis for me,” says Turner. “The songs were short, the line-up was minimal, the songs were very fast-paced. The music was more traditionally oriented toward metal. When everybody else joined, it took the songwriting another step further. Luke and I have a pretty big interest in noise music and feel that the hardcore audience could be receptive to that if exposed to it. We had been doing a lot of stuff together before he was a formal member of the band. We ended up just using a lot of that stuff on the record.”

OMG also represent a decidedly more lighthearted project than Isis — witness the rambling, old-school wah-wah solo Turner takes around the 22-minute mark of Seminar III. “There’s definitely no room for soloing in Isis. And not much in OMG, but that just seemed an appropriate place for it. We pretty much laugh at everything we do.” Especially when the drummer takes the microphone. Of all the group’s classic-rock studio pranks, Montano’s uproarious Glenn Danzig–aping vocal spot on Seminar II’s “Deserts in Your Eyes” got the most laughs. “That was probably the funniest thing that happened the whole time. Santos has been imitating Danzig for as long as I can remember, so he’s had a lot of time to work on it. Nobody laughs at OMG more than we do, that’s for sure.”

The jokes carry over to the discs’ song names and artwork: sample titles include “An Evening at the Gentlemen’s Club for Apes” and “Cinders of the Simian Psyche.” Meditations in B even has two monkeys hovering over a soundboard on the cover. Already renowned for the stunning layouts he creates for albums by Hydrahead bands as well as his own, Turner seems to be taking Isis’s recurring mosquito motif one step further with OMG. “The animal kingdom is my inspiration for everything. But this is on a much more humorous tip. I don’t honestly remember where the monkeys came from, other than Santos and I have a mutual amusement with monkeys. I think the music came first and the monkey theme incubated shortly thereafter.”

One thing OMG probably won’t be doing is touring. The band have played a total of three shows since their inception (two in Boston and one in Switzerland with Hydrahead signees Knut), and they have no intention of stepping things up anytime soon. “Our thing is going to be writing a bunch of songs, recording them, and then taking a break for four months. Playing live is really fun, but it’s just a big fuckin’ mess. Everybody is in touring bands. Trying to find the time to tour with those bands is hard enough. Trying to figure out when we can all do OMG together is just about impossible.”

But Turner does have a typically imaginative plan for bringing OMG to the masses. “We were going to do a franchise of OMG. You know, hire another group of musicians to do our songs. I’m going to see if I can auction that on eBay. I think we should do it in some bizarre place like Mexico or Alaska.” He pauses a second to consider the practicalities of the OMG franchise. “The problem with the franchise is, we don’t want them to do it better than we do it. And if they suck at it, we don’t want them to tarnish our lustrous name.”

ONE GIG OMG were expected to play last year but bowed out of at the last second was the annual New England Metal & Hardcore Festival, which this Friday and Saturday sets up shop at the Palladium in Worcester for the third straight spring. Featuring international cult legends Meshuggah, Amorphis, and Cannibal Corpse, it’s up there with the Milwaukee Metalfest and the New Jersey Metal Meltdown as one of the US metal underground’s premier annual events. And according to MassConcerts promoter John Peters, who books the festival, it may already be getting a leg up on its more-established competitors.

“From the feedback I get from within the industry — record labels, managers, booking agents — it seems like it’s become the best festival for this type of music,” says Peters. “We have a good place for it. It was an event created for the Palladium, really. It works really well with the two stages. You know, there’s a bar open — we all know metalheads like to drink.”

Peters feels the festival’s rock-friendly setting gives it an advantage over its counterparts in New Jersey (held last weekend at the Asbury Park Convention Hall with headliners Primal Fear, Cathedral, and Napalm Death) and Milwaukee (scheduled for August at the Milwaukee Auditorium). “You take this event and put it into an exhibition hall and try to separate the rooms with sound curtains — that just doesn’t work.”

This year’s line-up features an impressive array of Scandinavian prog-death favorites, including the only US appearance of the pulverizing Swedish group Meshuggah. “Every year we get a list from college radio programmers and people like that as to who they would like to see at the festival. We do our best to get what’s on that list. Meshuggah is the one act I particularly tracked down. They’re flying in on Friday, playing on Saturday, and going back on Sunday.” The synth-happy Finnish band Amorphis will cap off a rare week of North American dates at the fest; the Cannibal Corpse–headlined Spring Neck Break Tour will kick things off on Friday.

There’s also plenty of local action at this year’s fest, including a Saturday-night mainstage performance by New England’s breakout underground metal band of the year, Shadows Fall. Veterans of both previous festivals, the Massachusetts group have come to embody the increasingly metal-friendly nature of the local hardcore scene. As always, the hardcore/metal crossover will be in high gear: though Boston’s deans of metallic hardcore, Converge, had to cancel at the 11th hour, second-stage headliners All Out War and One King Down will be there to represent the East Coast mosh.

“When we first started the band, we wanted to shake people up a bit and show them there’s more to metal than sticking to one particular style,” says Shadows Fall guitarist Matthew Bachand. “Not only with what your band sounds like but the tours that you can do. The last couple of years, you’ve seen hardcore kids with backpacks at a black metal show. You never would have seen that three years ago, especially around here.” Coming off a solid year on the road with everyone from Amen to Glassjaw to King Diamond, Shadows Fall will take some time off after the festival to begin work on a new album.

Meanwhile, Peters has big things in mind for the future of the festival. “There are thoughts of packaging this event and going on the road with it. We’re trying to formulate an idea where we could put this on the road as an actual tour with maybe eight acts. It’s just hard finding rooms that really work. But once you work an event up to this level, it gets easier to book every year.”

The Third Annual New England Metal & Hardcore Festival is this Friday and Saturday, April 13 and 14, at the Palladium in Worcester. Call (508) 797-9696.