How does an indie rocker gain entry to the world of old-time roots music? The answer for guitarist Austin Vanasdale was simple -- start a band with a banjo player.

With Butler High school chums Matt Rychorcewicz and Eric Rodgers (the banjoist in question), Mr. Vanasdale moved into a South Side house and christened their band The Armadillos.

"We'd all been in rock bands previously," recalls Mr. Vanasdale. "I wrote songs by myself for a while. When I was younger, I was into indie artists like Bright Eyes and Sufjan Stevens. When I started playing with Matt and Eric, they introduced me to traditional music -- first the Kingston Trio, then Pete Seeger and Patsy Cline, then it got more old-timey like Hank Williams."

Mr. Rychorcewicz bought a mandolin and began learning it in earnest. The buddies scoured thrift stores and Jerry's Records for Cline and Williams records. He noted that unlike in bluegrass or newer roots music, where the mandolin might serve as a melodic or solo instrument, on older records the rhythm and fill elements were more prominent.

"The backing instruments aren't as important compared to the vocals, which are front and center as a storytelling [device]."

Gradually, The Armadillos evolved into an "old-time" band appropriate for the elegantly waxed handlebar mustache Mr. Vanasdale had cultivated.

"I always talked about it in high school, how I should grow a handlebar," he says. "There was this old guy who hung out at the Butler Eat'n Park and talked to us young kids smoking cigarettes and drinking coffee. He had a pretty decent-sized mustache, so I was inspired by that."

The departure of Mr. Rogers' banjo paved the way for another singer and songwriter to join the group.

"I responded to their Craigslist ad looking for a vocalist," remembers Sheila Liming, the co-founder of traditional Celtic band Callán. "I said, 'I can also play the accordion, are you interested in that?' They said yes, so I entered into a dual capacity. After a year, I started to contribute some of my own songs, so these days [Austin and I] write about half and half."

Both songwriters in the band deal with similar basic themes -- dark lyrics with bouncy melodies. The songs are often dour in subject matter, "like the Donner Party, or the Yorktown battle from the Revolutionary War," adds Ms. Liming. "Some themes are from contemporary life, like domestic abuse ['Eleanor'] or labor issues ['Working Man's Wages']."

The self-titled, DIY-pressed debut CD, which The Armadillos will release Saturday at Howlers, also includes "Crop Circles," which is about a malcontent with a short temper and itchy trigger finger, rather than spooky alien phenomena from a M. Night Shyamalan flick. Stand-up bassist Chuck Shrever, moved up from Florida with a background in punk and rockabilly and became the final piece of the puzzle.

"He worked with my friend at Church Brew Works," Mr. Rychorcewicz said. "I mentioned I was in an old-time band, and he mentioned being a bassist. I talked to Austin, who said 'Call him right now!' All of our friends played electric bass -- the upright was almost unheard-of."

On "Yorktown," Ms. Liming borrows Emerald Isle flair from Callån with her deft tin whistle playing ("a room-friendly version of the bagpipes"), capping off the lengthy production of the CD, which took nearly a year to assemble from recordings at McKeesport's Soundscape studio, where Anti-Flag did its most recent album.

"It was an adventure for them," recalls Mr. Vanasdale. "They told us they'd never done an acoustic band that was all strings and accordion."

Bengt Alexander, Howlers' house soundman, mastered the result to balance out the parts and make the group sound as live as possible. Male and female vocals mesh with the accordion, while the guitar and mandolin add intricate melodic interplay to the mix. The low-end thump of the upright bass, however, hits listeners in the gut.

"Chuck makes it easier for people to dance to our music," Mr. Vanasdale says. "We don't need a drummer because he's our percussion -- he even slaps the bass sometimes."

With groups like The Avett Brothers attracting a large, crossover audience, the time seems right for a Pittsburgh act like The Armadillos to grab similar reins.

"I think we're easily relatable to a younger crowd," Mr. Vanasdale says. "There's recently been a revival of not just folk, but [roots music] all across the board, and we fit into that."

"I've noticed the variety of bands we get put on bills with, ranging from punk and rockabilly to bands that are, compared to us, very electric like Southern rock," adds Ms. Liming. "We find ourselves playing with bands who plug in, even though we're still an entirely acoustic outfit."

Yet on their touring jaunts, The Armadillos also have been a hit with "geriatrics" in the South. "In Asheville, North Carolina, we do well among an elderly population that wants to hear traditional-sounding songs and put money in our case," says Ms. Liming.

"We strike a chord with them," adds Mr. Rychorcewicz, "since this is old-time music. There's a lot of bluegrass purism down there -- you'll see people play fiddle like you've never seen in your life."

So far, The Armadillos' touring luck has held, with only one or two poorly attended shows, and the out-of-town crowds are generally responsive. They graced the airwaves of Carnegie Mellon's WRCT-FM and the legendary community radio show, the Saturday Light Brigade, hosted by Larry Berger. But their ultimate goal, with a new product to sell, is the festival circuit -- not the jam-band fests so much as the folk events.

"They can be quite competitive, but I think that'd be a really good scene for us, because our music tends to appeal to a range of ages from young and old," says Ms. Liming. "The only thing is, the folk people might say we're too [lyrically] depressing for them."

With cannibalism and gunplay already in the can, will hangings and beheadings be far behind? "Well, we have a gallows song, but it's not on the CD," Mr. Vanasdale adds. "Give us time, though, and we might come up with a song about the history of the guillotine."

Critics Andrew Druckenbrod and Scott Mervis talk about music on "The Beat," available exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.