Mary Chapin Carpenter, Steve Earle and the Dukes, Mary Gauthier, Tracy Grammer, John Hiatt, Brother Sun, The Holmes Brothers, Little Feat, Mark Erelli, Lori McKenna, Atwater-Donnelly, Paul Thorn, Lucinda Williams, rockabilly queen Wanda Jackson, The HillBenders, Red Clay Ramblers, Roosevelt Dime and Spuyten Duyvil are among the dozens of artists and acts slated to perform during the 51st annual Philadelphia Folk Festival, August 17-19, at the Old Pool Farm in Upper Salford Township, near Schwenksville, Pennsylvania. The festival is produced and presented by the nonprofit Philadelphia Folksong Society. [To read the full article, click on the headline.]