Alt.country, or whatever you might like to call it, is a muddy row to hoe, with all manner of hard-to-document hybridization going on: witness the Gourds’ recent bluegrass cover of Snoop Dogg’s “Gin and Juice,” and the punked-out blues of chart-toppers like the Black Keys and Jon Spencer. Roots music in the hands of 21st-century musicians weaned on rock ‘n’ roll may be a head-scratcher to address critically, but in recent years, the alt-hinterlands of young blues and country bucks have been turning out startlingly heartfelt, honest music in the genuine spirit, if not the exact form, of the classics. Chatham County Line, with their second release, is certainly one of those. The Austin-based five-piece, who took Best New Band honors at the conservative RockyGrass bluegrass festival (clad in their vintage Opry-style three-piece suits and snappy hats) have turned out the musical equivalent of a Walker Evans photo-a rumpled, sepia-toned snapshot of pure, haunting Americana. Several tracks, like the mournful “Louisiana Freight Train,” recall more than a hint of contemporary twang merchants The Band. John Teer’s spooky fiddle and trilling mandolin on the instrumental “Gunfight in Durango” comprise an almost perfect sonic recreation of a vintage Western movie Narrative ballads like the gentle waltz “Parlour Light” and the plaintive “Arms of the Law” (“you’re in the arms of another/and I’m in the arms of the law”-there are few lyrics that capture the spirit of country music better) could have been unearthed from the dusty trunk of 78s in someone’s grandmother’s attic.