(This feature originally appeared in the Mountain Xpress.)

You’ve probably noticed how indie rock has grown a thick, burly beard. Coked-up art students who were ripping off new wave and post-punk at the turn of the century are nowadays smoking grass, scooting about in handcrafted Santee moccasins and basically reliving the early 1970s. A lot of these characters dress like total fruitcups, yet some of them make great music. Case in point: A few weeks back San Francisco’s Vetiver blew minds at The Grey Eagle with their laidback Muswell-Hillbillies-in-The-Big-Easy shtick.

At first blush one is tempted to slap this label on Baltimore’s Arbouretum.

Unkempt facial hair? Plenty.

Crunchy Crazy Horse riffage? Totally.

Improvisational jams that have nothing at all to do with Phish? You bet.

But despite these commonalities, the quartet’s aesthetic actually echoes a far older interface between indie rock and the days of patchwork denim and buckskin fringe. It’s a subtle, if at times shadowy, tradition stretching all the way back to hardcore: Black Flag’s marriage of punk, jazz fusion and bell-bottomed boogie; the Meat Puppets nicking tricks from The Dead and other country rockers; Bob Mould’s love for Richard Thompson/Fairport Convention; Souled American’s deconstruction of The Band; Red Red Meat feeding crusty blues rock thru warped tape loops. Then there’s Will Oldham (a.k.a. Bonnie Prince Billy), who, whether consciously or not, has transformed himself into the Neil Young of indie — if J. Mascis doesn’t mind, of course.

Although current trends have somewhat obscured this history, several newish bands carry the torch. In addition to Arbouretum, there’s Warmer Milks and D. Charles Speer & The Helix (who passed through town last December). But it’s our boys from Charm City who are the most accomplished of the lot. They’ve dropped three full-lengths and a split twelve-inch with Thrill Jockey labelmates Pontiak since 2006. Their latest, Song of the Pearl, released in early March, finds the band fine tuning its marriage of old school songcraft, psychedelic noodling and underground rock’s DIY idiosyncrasies. The album’s anthemic opener “False Spring” drones like druid-folk but quickly explodes into a snarling guitar squall equal parts Dischord-inspired post-hardcore and heavy duty stoner rock. Five tracks later the six-minute “Infinite Corridors” dives into a gnarled choogle before sprouting a latticework of screaming guitar runs that are twice as loud as the rest of the band — very Greg Ginn.

What’s cool is how organic and subtly blended Song of the Pearl feels. It’s obvious Arbouretum aren’t a bunch of Interpol-loving nerds who for some ungodly reason waited till their late 20s to discover Tonight’s the Night and Zuma. “In high school it was more about classic rock for me, but punk rock did factor into it as well,” explains Dave Huemann, the band’s singer, songwriter, guitarist and head honcho. “This was before the ‘alternative rock’ of the ‘90s. There was punk and hardcore, which I often liked, and stuff like The Cure or the Smiths, which I usually didn’t. I got on much better with the stoners anyway. They were way more laid back, hung out in the woods a lot, and didn’t care much for sports.”

Heumann the teenager learned something very important while skipping-out on study hall and cranking all that classic rock. Lets call it the, uh, two-for-one special. Back in them early ‘70s, rock & roll produced a slew of bands that slayed fans with both killer instrumental passages and thought-provoking lyrics. In addition to all the legends mentioned earlier, we’re talking about Peter Green’s Fleetwood Mac, the Groundhogs, and hell, even Black Sabbath (read the Lester Bangs article “Bring Your Mother to the Gas Chamber!”).

This beast is rare these days. The overwhelming majority of groups can do only one or the other, not both. Arbouretum is one of the few exceptions. A lot of the tunes on Song of the Pearl split my attention in two. I don’t know if I’m suppose to pay more attention the band, which is totally rocking out, or Heumann, who is dropping some serious knowledge. The songwriter claims he doesn’t possess a “very extensive background” in literature. Yet his narratives (see “Another Hiding Place,” a brooding depiction of infidelity) wander effortlessly from brutal honesty to dark and often abstruse introspection.

Arbouretum achieved the, uh, two-for-one special after stabilizing its once fluctuating line-up in the last year. “There’s this whole approach where one can be a singer-songwriter and get different guys to fill in here and there, which is totally valid,” says Heumann, who in the past has also worked with all the Oldham brothers: Will, Ned and Paul. “But after a while it just didn’t get the results I was looking for. In the current lineup not only can every one play really well, but every one has a really good sensibility in terms of the kinds of ideas they’ll pursue and what they’ll go for in an improvised setting.”

That refined sensibility also extends to Arbouretum’s fashion sense. Though the band possesses a deep fondness for all that vintage rock and folk, they don’t ever wear handcrafted Santee moccasins. That’s awesome.