The fourth solo album from former Drive-By Trucker Jason Isbell finds the singer-songwriter-guitarist writing and performing with new clarity, thanks in part to the one-two punch of newfound love (he recently married violinist-singer-songwriter Amanda Shires) and dedicated sobriety. The stunning, raw-boned waltz of opener “Cover Me Up” sets a tone of brazen vulnerability, followed by the balmy love song “Stockholm” (also, interestingly, a waltz), offering listeners assurance that the darkness ahead — brutal, timeless murder ballad “Live Oak” and the deliciously regretful “Different Day” — will be but shadows drifting across a mostly hopeful vista. Producer David Cobb (Justin Townes Earle, Shooter Jennings) keeps things simple, focusing on the bedrock of Isbell’s guitar — mostly acoustic — and increasingly expressive voice, making Southeastern disarmingly intimate. But Isbell’s six years with DBT will not go quietly, and he allows himself shots of Neil Young-inspired fuzz on anthemic “Flying Over Water” and barn burner “Super 8,” both nods to the horse he rode in on.