For mainstream country fans seduced by the chicken-pickin’ chops Brad Paisley displayed on last year’s Play, here’s a natural next step in your exploration of country instrumental music. As on Play, there are a few vocal ringers here—Tracy Byrd and Steve Wariner are among the singers who drop in to augment this trio of veteran Nashville touring and studio musicians. But the heart of Swamp Rat is in the pedal-to-the-metal interplay among guitarist Dan Cohen, bass player James Cook and drummer Derek Mixon, who prove that it’s possible to keep all ears riveted while rarely wasting a word.