A while back, Jason Isbell was in Muscle Shoals, Alabama, getting ready to receive the key to the city. In 1979 he'd had the mixed fortune of being born just across the river, in Green Hill, and he grew up in the area, sitting in with the town's legendary session musicians in the restaurants that were the only places that served alcohol in an otherwise dry county. “When I was 15 or 16, it was awesome, because they couldn't kick me out,” Isbell said. “I would stay there all night. Not so good when you're 19 or 20.”

We were in a restaurant in Nashville, not far from where Isbell now lives, as he told this story, and at the table he acted out what happened next. The mayor of Muscle Shoals approached with the key. “I asked the mayor, ‘Does this open up the jail cells?’ Because there was a time when I really needed to open up some of the jail cells. And he nervously laughed. He's a sweet dude. But you know, I've been to jail in that city a few times.”

By now, Isbell's been telling outlaw stories for nearly as long as he was an outlaw. On his right arm, he has tattooed seven notches, for seven years of sobriety; he marked his eighth in February. “I'm gonna get one more,” he said, looking down at his forearm. Drinking almost killed him; then it became his great subject. “That turned into my sword,” he said. Before, he told me, “I had a bunch of tools and nothing to build. I'm really glad I have something to build now.”

Since getting kicked out of his prior band, the Southern-rock outfit the Drive-By Truckers, and then getting clean in 2012, he's made some of the most shattering and redemptive music about sobering up—and then marrying the woman who helped you into rehab—that anyone has ever made, starting with Southeastern, which came out in 2013, and continuing through Reunions, which he plans to release this May. He's a traditionalist by training and inclination, and an open book by nature, and his music—some Southern rock, some country, a hint of good old confessional punk rock—reflects that. “I want somebody to get just as fired up about the content of the songs as they do about, you know, Neutral Milk Hotel,” Isbell said. “But also I want it to remind them of the radio when they were kids.” Dave Cobb, Isbell's longtime producer, told me: “He really treats it as if he was writing the last letter he ever wrote.” His concerts have become places of communion, where drunks and former drunks cheer at the sobriety lines and new couples wait anxiously for the songs about Isbell's own marriage, songs he often performs with his wife, the fiddler and songwriter Amanda Shires, who is a member of his band when she's not off touring with her own.

He's talked about those two pivotal years—the bottom, rehab, marriage, Southeastern—many times and will do so many times again. On tour he relives them every night. It would be human, you would think, to want to move on, to talk and write about something else. But Isbell isn't done with that time just yet. “I need to remember those couple of years,” he said. “If I ever get to a point where I feel like I don't need that anymore, then maybe I'll be ready to move past it. But my whole life changed. And almost exclusively for the better. Most people never get those two years in their whole lives.”