I can’t stop thinking about Jason Isbell’s teeth. A man with his history of cocaine and alcohol addiction shouldn’t have two decks of perfect shiny whites, but he does. Maybe they’re just a representation of his story, and his songs; all about surviving and restoring a life that shouldn’t have lasted this long.

Tonight’s audience at The Glasshouse knows his story. During Cover Me Up as he sings, “ But I sobered up, I swore of that stuff, forever this time,” the crowd burst into spontaneous applause. It releases a two-second smile on Isbell’s face, like a momentary lapse in his concentration.

Isbell’s records are consistently strong, but he takes every song to another level live, pushing them in new directions with the help of a tight rock and roll band. There’s not much chat with the audience. Isbell clearly doesn’t see much point in describing or introducing his songs. Instead, he fills every available second of this 2 ¼ hours set with material from across the best of the 400 unit, solo classics like Stockholm, and songs from his Drive By Truckers days.

These songs are rich in detail so, as powerful as his band are, everything hangs around his voice. Isbell has a thick, nasal Alabama drawl, curling every r to breaking point. But when his voice opens up within these perfect acoustics, it’s the most powerful instrument on stage.

Jason Isbell has settled into a niche at the Americana end of country rock he shares with artists like Ray Lamontagne. But only live could I truly appreciate him as a guitarist. He gives us bluegrassy acoustic breaks Billy Strings would be proud of, and a succession of blazing guitar duels with his prodigy Sadler Vaden. I see echoes of Robbie Robertson and Eric Clapton going at it during The Last Waltz. Playing Danko/Manuel from his Drive by Truckers period is a nod to that source of inspiration.

At a time when plenty of country singers trade in cliches, everything Jason Isbell sings sounds real. But I still wonder if teeth that would make a Bee Gee jealous really can be.

Ross McCall