Jason Isbell and the 400 Unit, “The Nashville Sound” (Southeastern Records)

Produced by Dave Cobb, who also works with Grammy winners Chris Stapleton and Sturgill Simpson, this record is their third collaboration (after 2015’s Something More Than Free and 2013’s Southeastern). These ten new songs shore up any doubt critics may have had that Isbell is one of the best singer-songwriters of our time.

On “Last of My Kind,” Isbell shows the musical and lyrical influence of his friend and mentor, John Prine. The tune is reminiscent of Prine’s “In Spite of Ourselves,” but its narrator is more serious behind the rhymes. “Old men sleeping on the filthy ground/ Spend their whole day just walking around/ Nobody else here seems to care/ They walk right past them like they ain’t even there.”

“White Man’s World” is a blues-based election elegy sung for Isbell’s daughter, grateful for the “fire in my little girl’s eyes” that keeps hope alive. Isbell sings a verse, “Thought this world could be hers one day, but her mama knew better,” and Shires answers with a defiant fiddle whine. “I’m a white man living in white man’s town/ Wanna take a shot of cocaine and burn it down/ Mama wants to change that Nashville sound/ But they’re never gonna let her.”

But Isbell and Shires decided to carry on and change it together. They leave us with a powerful sense of peace, the kind of feeling shared “on the porch on Sunday nights.” Isbell ends his fight with “Hope the High Road” and finishes the record with a string blessing, “Something to Love,” singing: “I hope you find something to love/ Something to do when you feel like giving up/ A song to sing or a tale to tell/ Something to love, it’ll serve you well.”

The Nashville Sound is Isbell and Shires’. It’s their porch we sit on listening, witnessing their music spread across the horizon all over Americana.