It doesn't quite qualify as a provocation that Jason Isbell chose to call his new album with his band the 400 Unit The Nashville Sound.
Still, it's a statement of purpose, a confident expression made by a mature artist at the peak of his power.
Isbell, who played a terrific just-short-of-two-hour show at the Fillmore on Monday night with the five-man 400 Unit expanded to include his fiddle-playing and singing wife, Amanda Shires, is on a stunning three-album winning streak that began with 2013's Southeastern and continued with 2015's Something More Than Free.
The Nashville Sound was the label hung on the polished productions, often including choruses and string sections, pioneered by Chet Atkins and Owen Bradley in the 1950s. And Nashville, of course, is the place where the slick pop sounds that dominate country radio have been produced for decades.
But Music City is also home to a songwriting community that draws on country and folk traditions, looks to artists like John Prine and Bob Dylan for inspiration, and embraces Southern roots while also rocking out with confidence. And Isbell, formerly with the Drive-By Truckers, stands at the absolute top of that heap.
The Nashville Sound is Isbell's third album since getting clean and sober and his first since becoming a father. It's full of tender songs that treasure the times spent with loved ones as of the highest value — "If We Were Vampires," sung with Shires toward the end of the show on Monday, is particularly gorgeous and affecting.
But the album is also rich with character-based songs, like "Cumberland Gap" and "Last of My Kind," in which the 38-year-old Isbell, an Alabama native, writes and sings with insight and empathy about men who share his demographic profile but who are more likely than he to have voted Republican in the presidential election.
And in "White Man's World," he sings in the first person as he reckons with the South and America's history of racism and insists there's more glue that holds Americans together than there is strife tearing us apart. "If you're still breathing, it's not too late," he sang. "We're all carrying one big burden, sharing one fate."
Isbell alternated acoustic folkish songs with electric bruisers through the night and sat in with Shires, who opened the show, on slide guitar on her cover of the Allman Brothers' "Midnight Rider." He told a couple of unexpected Philadelphia stories. One was about visiting a friend as a 20-year-old at the turn of the millennium on his first trip outside the South and being taken by surprise by the Mummers Parade, the other about getting tattooed backstage when he was in town on tour with simpatico Nashville songwriter Chris Stapleton on Father's Day weekend last year.
The set list drew from Isbell's impressive troika of recent albums. The sturdy songs, with not a dud in the bunch, were spiced with Shires' fiddle, as well as with accordion or fiery lead guitar as necessary. Songs Isbell wrote about growing up Southern during his tenure in the Truckers in the '00s, like "Decoration Day" and "Outfit" were greeted with fist-pumping enthusiasm by a singing-along crowd. And the show came to a scorching close with another tribute to the late Gregg Allman on "Whipping Post."