Robert Earl Keen is elemental to the Texas music tradition, as proven by rootsy partnerships with other top-shelf Texan singer/songwriters. He and Lyle Lovett wrote the wistful heart-tugger "This Old Porch" together, and their weathered voices are the perfect complement for each other in a duet. And his bluegrass-tinged take on the traditional "Wayfaring Stranger" is illuminated by a guest vocal from Dixie Chick Natalie Maines.