JIMBO MATHUS White Buffalo jimbomathus.com Back in the ’90s, while leading Squirrel Nut Zippers, this Mississippi native scored a novelty hit with “Hell,” a hot-jazz tune that snuck onto alt-rock radio. A decade after the Zippers’ demise, Mathus isn’t doing anything quite as radical or conceptual. White Buffalo is a genre record, the genre being Southern—a sweaty, twangy sound informed by country, folk, gospel, soul and good ol’ rock...