In Comets on Fire, Ethan Miller's guitar and voice are often caked in layers of echo and distortion, but, in his own band Howlin' Rain, he sounds like a hard-rock traditionalist. The group honed a summer-barbecue vibe on the recent Magnificent Fiend, filling out swampy rhythms with dueling electric guitars and hoarse moans reminiscent of the Black Crowes. Fans of open-tuned guitar should come early to see Mark Fosson, a Kentucky player who cut some excellent tracks for John Fahey's vanguard Takoma Records back in the '70s.