Eight years ago Prine was discovered in a Chicago pub by Kris Kristofferson, but he has yet to enjoy real commercial success. The reason, most likely, is one of style. Faded-denim folksiness and a Midwestern twang that makes “Bible” sound like “babble” rarely find their way into Top 40 play lists. Prine’s homespun artistry is considerable, nonetheless, and on his new album the former Chicago mailman focuses on boy-girl, love-and-loneliness problems rather than the blue-collar blues that characterized his best early work. The wry humor is still there, as when he complains to an absent lover: “You been on my mind so long/You must be livin’ up there.” Signs of new maturity are also present. He sings in Sleepy-Eyed Boy, “Where are the boot straps/To lift myself up/Where is the well/Where I once filled my cup?” Happily for Prine and his fans, the well hasn’t run dry.