Odd sounds seem to be coming from a dusty tent. It’s not quite a revival, but a revival of American roots music generated by devotees of artists as diverse as Julie Miller and Gillian Welch, Gram Parsons, Loretta Lynn, Tammy Wynette, Patsy Cline, Melba Montgomery, Hank Penny, The Louvin Brothers, Kasey Chambers, Ralph Stanley, Jimi Hendrix, The Davis Sisters, Emmy Lou, Ryan Adams, Lattie Moore, Dorsey Burnette, Nick Lowe, Jolie Holland, and Freakwater.