The title track on Hayes Carll’s fourth album, KMAG YOYO, is based on the acronym “Kiss My Ass Guys, You’re On Your Own,” and it follows a second-generation soldier who gets recruited for black-ops medical experiments after one too many fuck-ups in the field. It’s a cranky, funny, war-torn character sketch to rival the best of Steve Earle, and it defines the mindset of KMAG YOYO (& Other American Stories), a scruffier follow-up to Carll’s more trad-minded Trouble In Mind. Reportedly born of Carll’s desire to capture the rough-hewn energy of his touring band The Poor Choices, KMAG YOYO was largely written in the studio, built from riffs spawned in rehearsal jams. The spontaneity isn’t always the best showcase for Carll, who has a tendency to lean too often on either his mid-’60s Bob Dylan cadence or his two-stepping Hank Jr. voice. But Carll remains one of the brightest, funniest lyricists in contemporary country-rock, as evidenced by his duet with Cary Ann Hearst on “Another Like You,” in which she plays a sassy right-wing barfly and he plays a hardcore leftist who falls head-over-heels for her. The scenario is humorous, the lyrics are incisive and self-deprecating, and the band is appealingly loose. It’s a song that sticks, in a genre where that’s increasingly rare.