NEW ORLEANS — A downpour accompanied by thunder and lightning soaked the New Orleans Jazz and Heritage Festival on Sunday morning shortly after the Fair Grounds Race Course opened its gates.

Despite the tough start, the largely outdoor music festival proved its resilience, carrying on with music on multiple stages. Attendance stayed sparse, though, through the early afternoon.

During the worst of the storm, at about 11:30 a.m., only a few dozen diehard music lovers moved to the rhythm and chant of the Golden Star Hunters Mardi Gras Indians, who performed at the Jazz and Heritage stage. Nearby, the long line of food booths had just two patrons.

The weather improved, and by the time genre-bending New Orleans saxophonist Khris Royal and his band, Dark Matter, started their 12:30 p.m. set at the Gentilly stage, sunlight brightened the soaked Fair Grounds.

When the Nevilles performed their 3:10 p.m. show at the Acura stage, people had arrived to the Fair Grounds in large numbers, making Sunday look much less like a washout.

The Nevilles — basically the Neville Brothers band without Aaron Neville — made their Jazz Fest debut Sunday even though members of the Nevilles have performed at the festival dozens of times during its 44 years. The group, including brothers Art, Charles and Cyril Neville, and second-generation Neville cousins Ivan and Ian Neville, had no trouble conjuring up a funky set.

“We got a bunch of Nevilles up here,” Art Neville said from behind his keyboard. “We’re missing one brother. Wish him all the best. He’s doing his thing. We’re doing our thing.”

The rain returned in time for Acura stage headliner the Dave Matthews Band’s 5 p.m. show. Even Matthews got soaked as he played for a big crowd of rain gear- and umbrella-covered fans.

Come rain or shine, the festival resumes Thursday-Sunday for its second weekend at the Fair Grounds Race Course. Festival gates open at 11 a.m.

The second weekend features New Orleans rhythm-and-blues star Frank Ocean; classic rock act Fleetwood Mac; pop-rock’s Maroon 5; Willie Nelson; classic reggae artist Jimmy Cliff; pop-soul duo Hall and Oates; and punk-rock-poet Patti Smith, among many others.