At its heart, the Minnesota State Fair is a giant party. Essential to any party is the music, and on Saturday, Sept. 5, the Preservation Hall Jazz Band and the Avett Brothers turned out two breathlessly generous sets of music that elevated the mood at the state’s biggest party from celebratory to transcendent.

Music fans began filtering into the Grandstand as dusk approached, and The Current’s Bill DeVille spun tracks to welcome the crowd. The Preservation Hall Jazz Band’s instruments were already set in place, and many fans wandered up to the stage to get a photo of Joe Lastie Jr.’s kick drum or Ben Jaffe’s tuba, each emblazoned with the band’s name.

After Jim McGuinn’s brief introduction, the Preservation Hall Jazz Band launched into a New Orleans jazz setting of Albert E. Brumley’s hymn, “I’ll Fly Away.” From that point forward, it was nonstop music. As they played, it was as if the PresHall band ushered in the sunset as well as coaxing music lovers away from the concessions and into their seats.

As the band played on, each member got to show of his chops, with highlights including solos and stabs from Charlie Gabriel’s clarinet, Clint Maegden’s sax and Ronell Johnson’s trombone (on which he even quoted War’s “Low Rider”).

The band finished up with a medley that included NOLA-jazz takes on the Jackson Five’s “I Want You Back” and Stevie Wonder’s “Sir Duke.” And when the audience clamored for an encore, the PresHall band obliged by picking up from the fadeout of “Sir Duke.” The breakdown concluded with a New Orleans-funeral-style procession offstage that culminated in a shallow incursion into the crowd, met by a surging phalanx of smartphone-wielding fans. The PresHall band eventually retreated into the backstage area, accompanied by enthusiastic appreciation from the audience.

The festive mood was well established when The Current’s Lindsay Kimball took the stage to introduce the Avett Brothers, whom she called one of her favorite bands, a sentiment echoed to her by those gathered in the Grandstand.

Night was firmly setting in when the Avett Brothers’ drummer Mike Marsh and violinist Tania Elizabeth took the stage, issuing the eerie prelude to “Satan Pulls the Strings” as white and red spotlights mingled in fog effects, bringing the entire floor area of the Grandstand to its feet. The rest of the band came onstage, filling out the arrangement of the song. They segued seamlessly into “Live and Die,” and from that point onwards, the Avett Brothers had the Grandstand audience in the palms of their hands.

With the endurance of elite marathon runners, the Avett Brothers hardly left a second without music in it. Occasionally they would give each other space, allowing for solos by each of the band members, including a monster drum solo by Marsh and a bathed-in-spotlight, fiddle-and-vocal turn by Elizabeth. Scott Avett tugged at heartstrings with his solo turn at “Murder in the City.”

Throughout the show, Scott Avett transitioned from banjo to piano to guitar and back to banjo again, running back and forth across the stage with bottomless vigor. Seth, meanwhile, kept churning out guitar rhythms and riffs, frequently bouncing or running in place to the beat of each song, bassist Bob Crawford and cellist Joe Kwon matching him for musical and kinesthetic output. On those tunes with a waltz tempo, many of the band would box-dance in a line formation, bringing a playfulness to complement the buoyant energy that permeated the show.

And although big-screen closeups of Scott at the keys revealed sweat dripping from his chin, a sultry night in Minnesota is certainly no obstacle to a band with its roots in Cabarrus County, North Carolina.

Like their openers, the Avett Brothers maintained an economy of words, letting the music do the talking. Seth Avett made a brief and sincere speech of appreciation for the Preservation Hall Jazz Band, inviting the audience to give PresHall another round of applause (to which the audience responded generously) and calling PresHall “musical perfection.” But then it was time for the Avetts to deliver musical perfection of their own, continuing their movement from song to song to song with jaw-dropping pace.

Ostensibly concluding with a one-two of “Talk on Indolence” and “Hand-Me-Down Tune,” a lengthy and sustained applause by the audience coaxed an encore from the Avetts, who launched into a rollicking and true-to-the-original cover of John Denver’s “Thank God I’m a Country Boy.” The second song of the encore was “Kick Drum Heart,” which was punctuated by a searing guitar outro by Seth, playing an arch-top electric guitar.

The final song was a spot-on capstone. “I and Love and You” not only drew a wistful close to a memorable concert, it echoed the tacit melancholy that accompanies the Minnesota State Fair’s heralding of summer’s end.

Setlist – Preservation Hall Jazz Band

“I’ll Fly Away”

“Go to the Mardi Gras”

“Corinna, Corinna”

“I Think I Love You”

“Tootie Ma is a Big Fine Thing”

“Sugar Plum”

“That’s It!”

Medley: “I Want You Back”; “Sir Duke”

Encore:

Variations on a theme of “Sir Duke”

Setlist – The Avett Brothers

“Satan Pulls the Strings”

“Live and Die”

“Morning Song”

“Will You Return?”

“Down With The Shine”

“Head Full of Doubt”

“Vanity”

“Ramblin’ Fever” (Merle Haggard cover)

“Slight Figure of Speech”

“Murder in the City”

“Salina”

(Solo by violinist Tania Elizabeth)

“Die Die Die”

“Winter in My Heart”

“The Prettiest Thing” (David Childers cover)

“Paranoia in B-Flat Major”

“Laundry Room”

“I Killed Sally’s Lover”

“Another is Waiting”

“Talk on Indolence”

“Hand-Me-Down Tune”

Encore:

“Thank God I’m a Country Boy” (John Denver cover)

“Kick Drum Heart”

“I and Love and You”