Too many country-music purists of the past couple decades brag about keeping the true sound of country alive. Oklahoma native Jason Boland, though, just does it. Bearing a catalogue of gritty, twangy songs that sound as natural as falling off a horse, Boland and his Stragglers have spent the last ten-plus years crisscrossing the nation and building a grassroots following, one that knows and feels authentic Americana when it hears it. The group's latest full-length, Comal County Blue — and particularly its keening, fiddle-laced single, "Bottle by My Bed" — is a rich, deep and elemental work that doesn't sound retroactive as much as it yanks out country's roots and replants them in the modern world. Boland's show Sunday night at the Bluebird completes a four-night mini-tour of Colorado and Wyoming that's being recorded for the live album High in the Rockies, due this April.