Dierks Bentley's mop of curls is his career barometer. Untamed and devoid of style in 2003, they gamely accompanied his enjoyable but superficial debut. By 2005's Modern Day Drifter, the weave was tempered with Merle-loving grit and a handful of bona fide country radio hits. 2006? Backlit dramatics. He was a star now. As for 2009's Feel That Fire or his latest, the bluegrass-tinged Up on the Ridge, well, Dierks' rough-cut layers make it clear he's as interested in singing and songwriting as he is in Victorian literature and aluminum siding. He's a redneck Renaissance man.