What the swamp-boogie badasses in Th' Legendary Shack*Shakers lack in fancy manners and social graces, they make up for in scope and ambition. Singer and harpist J.D. Wilkes refers to its most recent album, Swampblood, as the final installment of the band's "Tentshow Trilogy." While earlier albums dealt with faith revivals and freak-show carnival barking, Swampblood delves deeper into the Southern-gothic-hued heart of darkness. Luckily, you don't need to know the back story to enjoy the rough-hewn roots-rock and hillbilly stomp of the four-piece band. This time around, the lurking doom of heavy metal peaks out from the corners of the Shakers' banjo plucks and harmonica hurricanes, giving a heaping dose of doom and gloom to these songs of sin and redemption.