By Clea Simon

At 70, Marcia Ball is a nonstop pro, particularly at pacing. Early barn burners gave way to the slow blues of “Just Kiss Me.”

Singer Marcia Ball — at ONCE she hit her vocal marks with aplomb.

You can count on Marcia Ball. Even with a cold rusting her voice, as it appeared to be doing Tuesday night, you can trust the Louisiana music stalwart to deliver rollicking sing-alongs interspersed with virtuosic barrelhouse piano in a style uniquely her own.

From the swinging boogie-woogie of her opener, Albert King’s “Let’s Have a Natural Ball,” through more beat-heavy standards, like her now classic take on Muddy Waters’s “Red Beans,” Ball hit her marks with aplomb. Working in the ornate syncopated style of such late greats as Professor Longhair, Allen Toussaint, or Dr. John, the singer-pianist toyed with her melodies, ornamenting her fills and solos with the vaguely Caribbean groove of New Orleans piano, all the while keeping the rhythms rolling with a decisive left hand — a little less pretty than Toussaint, a touch bluesier than Fess, as she brought her Texas roots into the Crescent City mix.

Tuesday night’s show wasn’t at her late ice-house-turned-music-hall Zona Rosa, in her hometown of Austin, nor a regular stop like uptown NOLA’s Tipitina’s, however. Although Ball was playing on Mardi Gras night — the “dregs of Mardi Gras,” she noted — she faced a sadly deficient house at ONCE in Somerville (the show had been moved from the Wilbur Theatre), three-quarters full at best. Still, at 70, Ball is a nonstop pro, particularly at pacing. Those early barn burners gave way to the slow blues of “Just Kiss Me,” and if Ball’s raspy vocals weren’t quite up to the torch-song lyrics, her right hand was, detailing a series of sweet trills that made up for any lapse.

It helps that Ball’s band — guitarist Mike Schermer, longtime bassist Don Bennett, drummer Mo Schonhorn, and tenor sax player Eric Bernhardt — are all aces, and she wisely gives them room to play. Of course, even when Schermer took over for a break, the through-line of her piano continued, though subordinated to fills and one fast solo as the guitarist whipped through his catchy swamp boogie “She Won’t Be Coming Back.”

Sonny Landreth — at ONCE he displayed his inventive and agile style.

That same generosity comes out in Ball’s lyrics, too. Whether it’s the social and political heroes listed in “Life of the Party” (from her latest recording, 2018’s Shine Bright), such as Susan B. Anthony and Justice Ruth Bader Ginsburg, or musical heroes, she shares the stage freely. By the time she wound up to her own now-classic “That’s Enough of That Stuff” — name-checking New Orleans greats from Irma Thomas and the Neville Brothers to the lesser-known (around here) Shirley and Lee — she had energy enough for all. Perhaps the music gods heard her: As she moved into the bittersweet blues of “The Squeeze Is On,” Ball’s voice opened up. By “Louisiana 1927,” the Randy Newman ballad that has taken on new poignancy after Katrina, the strain was barely noticeable. The sound of tears, perhaps, and set against the beauty of her sensitive playing, that only made it more heartbreaking.

But this was a party, after all. And that meant the beat came back hard and heavy with a romp through the pure risqué fun of “Play with Your Poodle” and, finally, “The Party’s Still Going On,” a socially conscious story set to a Little Richard beat. The audience may have been seated, but this was Mardi Gras, still, and by the end of her nearly 90-minute seat, she’d roused more than a few New Englanders to their feet.

Sonny Landreth’s opening set presented a different side of Louisiana blues. The slide guitarist started off acoustic, singing the zydeco-inflected rocker “Creole Angel” almost as a ballad in his reedy voice, before the band (bassist Dave Ranson and drummer Brian Bignac) switched over to electric. With the power on, he smoked through classics such as Robert Johnson’s “Walkin’ Blues” and Elmore James’s “It Hurts Me Too,” but Landreth also took the time to linger over his own spacy instrumental “Brave New Girl,” showcasing both his inventive and agile style of playing and a lyrical sensibility.

Clea Simon’s most recent novel is An Incantation of Cats: A Witch Cats of Cambridge Mystery. She can be reached at www.CleaSimon.com.