Local quintet The Lost Sea plays mellow, rustic, harmony-laden alt-pop.

The leadoff tracks "So Little to Lose" and "Warmer Weather" wouldn't be out of place on Triple-A radio or an episode of "Austin City Limits." So why is its debut EP released on Atomic Family, a label that has up to now mostly showcased acts from the area's DIY folk-punk scene? Songwriter/guitarist Sean Atkins explains how these two seemingly disparate musical threads merged.

"The Lost Sea started as my own solo acoustic project," he recalls. "It felt boring to play, like the songs were empty, so I wanted to expand the sound and make it more dynamic."

Atkins was friendly with pianist Becki Gallagher (of indie-pop band Bridgley Moore) and bassist Andrew Belsick, so they hopped on board and searched for other musicians through Craigslist. Though the EP was recorded with another friend, Chris Weaver, on drums, the lineup eventually settled down with new drummer Frank Schlatterer and lead guitarist Andre Cuneo.

This isn't Atkins' first band to hit local venues. Scenesters from the turn of the decade might remember him from emo band Owen's Ring (at the time when emo still meant emotional indie-rock songs, not hairspray, eyeliner, and self-cutting). "I was listening to the Promise Ring and Pedro The Lion -- all that stuff on Jade Tree Records -- and also older guys like Tom Petty and Johnny Cash."

More recently, the weekly AcoustiCafe event at Club Cafe gave Atkins the confidence he needed to flesh out his own compositions. "My friends told me I should go see how people feel about the songs, and start hitting up open mics. [AcoustiCafe] is a supportive environment where everyone wants to get better. You can go up to someone like Brad Yoder, who has played acoustic for a while. Everyone there has been really great and helped me out a lot."

His decision to associate with Atomic Family came from South Hills boyhood chum (and label honcho) Erik Grieco. "He had seen us live, and a few weeks later I mentioned to him that we were working on an EP [recorded with Jake Hanner of the band Donora]. He jumped right on it and asked if we wanted to put it out on Atomic Family. I really respect what he's doing -- trying to bring the scene together. It's amazing how they started a label out of basement recordings in his house. They had their own booth for three dates on the Warped Tour. It's impressive that he's working so hard."

The Lost Sea does its part to promote itself, gracing clubs from the Bloomfield Bridge Tavern to the Lava Lounge and Club Cafe. When asked if his band is affiliated with the groups from the recently released "Key Party" compilation (for example, Lohio, Boca Chica and Emily Rodgers, all of whom get airplay on WYEP), Atkins says not yet, but he's looking forward to it. "We are playing shows with some of those bands, and we definitely fit in with their sound."

Right now, however, he's concentrating on the next two shows The Lost Sea has scheduled -- Friday at the Brillobox with The Takeover UK and Meeting of Important People (10 p.m., $5) and Aug. 22 with New York City chamber-folkies Gregory & The Hawk at Modern Formations Gallery (8 p.m., $8).

So if you're looking for a local breakout band with a bit of Conor Oberst and a bit of David Bazan, The Lost Sea will certainly fill the bill.