Offering further proof of what a tight and creatively restless band they are, this fourth release by the Legendary Shack Shakers finds them again tweaking their possessed blend of blues, country, and rockabilly to deliver the swampy sound promised in the title. The Balkan gypsy touches of their last release have been replaced by a bayou-flavored boogie that lives somewhere between the Delta and Appalachia, with scorching harp, frenzied piano, and guitars dripping with reverb. Featuring 16 songs in just over 30 minutes, the tunes flow along smoothly from style to style, moving from sly tent revival gospel (“Born Again Again”) to spot-on mountain jug band (“Jimblyleg Man”) to righteous rockabilly (“He Ain’t Right”). Frontman Colonel J.D. Wilkes’ lyrics conjure up colorful images of feral beasts, sepia dreams, cattle stuck in oak trees, biblical floods, and other signs of a Southern Gothic apocalypse, and the energy and drive of the band never eases up. Swampblood reveals a crack — and cracked — band at the height of its considerable powers.