If there was ever any question about whether it’s possible to put on an old-school, live-broadcast barn dance stocked with varied Americana lineups and draw capacity crowds week after week, it’s been answered definitively. Music City Roots is celebrating its three-year anniversary. There’s a folksy yet fun and not overly reverent flavor to the repartee between announcer Keith Bilbrey and host Jim Lauderdale, not to mention the Vietti Chili girl’s jingles. Plus the beer, biscuits and legal moonshine flow freely. Della Mae, one of the acts playing MCR’s anniversary show, is an all-female bluegrass quintet with a folk-rock kick, a bluesy spitfire of a vocalist and a grasp of tragic trad-style balladry to rival any of the bearded latter-day bands reviving the era of The Band. That’s familiar territory for the country-rock string band Marley’s Ghost, too. And speaking of anniversaries, those guys just marked their 25th by releasing their Cowboy Jack Clement-produced Jubilee album.