Had they grown up a few states to the north, Seth and Scott Avett would have been fitting faces in a sea of punk rockers. But these brothers dug their roots in the soil of Greenville, N.C., and that's what makes them all the more interesting. Playing rock music in a town where bluegrass nights are a staple of the local pub scene gave the siblings more avenues to explore, and when their brash bar bands dissolved, it made sense to give country a try. Jump ahead about three years to the main stage at last summer's Philadelphia Folk Fest, where it sounded like the Avetts (also featuring upright bassist Bob Crawford) were informing a reverent take on Appalachian roots music with the vim and vigor of The Pixies. Seth shrieked till his neck veins bulged, then ripped strings from his acoustic guitar, while Scott fell to his knees, his hair flopping across his eyes, his fingers still plucking his banjo. An intense sound, but one that would make total sense coming from bourbon-slugging lumberjacks gathered 'round a campfire in the early 20th century. The Avetts' recorded output has previously suffered from studio attempts to temper their sound; despite strong songs, 2004's Mignonette unfortunately sounds like the byproduct of a calmly seated trio of prim and proper players. Their new Four Thieves Gone: The Robbinsville Sessions (Ramseur Records), due out in February, does a much finer job capturing the wild-eyed, whiskey-fueled bunch we'll see screaming up the TLA next Wednesday.

Wed., Jan. 18, 8 p.m., $15, with BR549, The TLA, 334 South St., 215-922-1011, www.thetla.com.