“I sobered up and I swore off that stuff, forever this time,” sings Jason Isbell on “Cover Me Up,” a world-weary love song that shows the Alabama native isn’t averse to autobiography. It also suggests that rehab has sharpened his country-rock storytelling. Here, he mostly dials back the volume to plumb heavy emotions. New wife Amanda Shires and Kim Richey add harmonies to rich songs about love’s struggle. But “Elephant” is the masterpiece, a piercingly plainspoken song about friendship and cancer that concludes, “One thing that’s real clear to me/No one dies with dignity.” Maybe, but he proves you can sure as hell make art with it.