Chatham County Line formed just a year or so before the soundtrack to the film O Brother Where Art Thou changed the musical landscape, putting a wind at the back of the Raleigh quartet’s bluegrass-inspired sound. While never the type to kowtow to purists, their first couple albums were close to the soil with sweet, lonesome harmonies, a dusty rustic palette, and plenty of songs about trains. Last year’s Wildwood offers less smoky ballads and more ’60s rock, folk, and country, evoking Gram Parsons, Bob Dylan, and Neil Young. “We love listening to stuff with pedal steel, drums, and different flavors and different attitudes,” says singer/guitarist Dave Wilson. “I love when you go to see a movie and they don’t tell you what year it is because it’s kind of an amalgam of different years. I love that attitude, and that’s part of what our instrumentation provides us.” Wilson, bassist Greg Readling, fiddler/mandolin player John Teer, and banjoist Chandler Holt headline the main stage at 9 p.m. Local combo Flatt City plays the deck at 5 p.m.