Not long into Keith Urban’s set Friday at the Acura Stage, he paused and sang, without accompaniment, the Creedence Clearwater Revival chestnut “Have You Ever Seen the Rain.”

Then everybody saw it. Forty-five minutes into his headlining set at the New Orleans Jazz and Heritage Festival presented by Shell, a thunderstorm ended the music for the day.

Urban told his audience that festival representatives were telling him to wrap things up. Even he admitted it was risky to stick around: “I don’t like that lightning,” he said as the sky lit up.

Indeed, other day-ending headliners including Wilco and Jimmy Cliff were yanked from their respective stages 15 minutes earlier.

“Day 1 of Jazz Fest concludes at 6 pm due to the possibility of severe weather. Here’s to a sunny Sat & Sun!” the festival tweeted about 15 minutes before Urban’s set ended.

By 6:40 p.m., the rain had stopped and the sun returned, but by then, the Fair Grounds was largely empty.

Before the soaking, Urban and his band played a brief set of material heavily influenced by 1980s guitar rock, from Boston to the Police. Songs like “Put You in a Song,” “Long Hot Summer” and “Good Thing” showed he and his band are masters of polished craftwork, kind of like the stuff he reviews on “American Idol.” Dressed in a black T-shirt with Johnny Cash’s silhouette on the front, the New Zealand-born Urban handled most of the lead guitar duties.

When a light drizzle grew heavier, he turned to slower acoustic material — “I’m gonna be there to meet you with a warm, wet kiss,” he sang on “Making Memories of Us,” and the crowd roared.

Even as rain drizzled periodically throughout the afternoon, the opening day of the seven-day festival reflected homegrown dexterity on all stages.

Hometown singer Mia Borders was an early highlight on the Gentilly Stage. Wearing a Team Gleason jersey and playing bass, she performed a set reminiscent of Bill Withers, with slow grooves that highlighted her rich vocals.

Besides the Jazz Tent, where local heroes like trumpeter Nicholas Payton were performing, jazz students from the New Orleans Center for Creative Arts headlined at their own tent a short distance away.

At the Sheraton New Orleans Fais Do-Do Stage, Cajun and zydeco bands bookended the day, but the stage also featured music that stepped outside the genre, such as La Santa Cecilia, a Los Angeles band that also used an accordion to get the crowd dancing to cumbias and bossa novas.

Another roots music alternative was local singer-songwriter Paul Sanchez, who played with not one but two bands during his one-hour set. The first was Minimum Rage, an all-female band that took turns showcasing a variety of quirky roles. Guitarist Sonia Tetlow sang a song about mobile food vendor Mr. Okra, and drummer Linda Bolley fired off a guitar solo during a cover of Johnny Cash’s “Ring of Fire” even as her feet kept the beat, banging the bass drum and high-hat cymbal. Bass player Mary Lasseigne stepped into the title role of “Maggie Don’t Two-Step,” a Cowboy Mouth song that got the crowd to do what they’re supposed to do at a stage named Fais Do-Do: dance.

Midway through the hour, the women’s band stepped aside for the Write Brothers, a new ensemble featuring Sanchez that released a debut album this year. The group, featuring songwriters Spencer Bohren, Jim McCormick and Alex McMurray, is reminiscent of “Workingman’s Dead”-era Grateful Dead. All four leads traded vocals equally over four songs that ended with “We’ll Be Together Again,” a Celtic-inflected song that also would be appropriate at a funeral held at a bar. As a vocalist and guitarist, McMurray is the group’s secret weapon; when he crouched to fire off a solo on his steel guitar, he literally lost his hat.

When Irish singer Andrew Hozier-Byrne headlined the Gentilly Stage, he delivered the hit song (“Take Me to Church”) that earned him international prominence last year, but he also showed he is a devotee of the Hill Country blues of northern Mississippi and contemporary neo-soul.

Known as Hozier, his voice and songs equate secular yearning with spiritual bliss in a way that’s reminiscent of the late singer Jeff Buckley. His band, which included a cello player, showcased songs like “Sedated” and “Arsonist’s Lullaby” that were driven by fat gospel piano chords and steely rock guitar riffs.

Early in the set, he brought blues guitarist Alvin Youngblood Hart to the stage for both a tribute and a collaboration. “I have been approximating his style every night on this tour, so it’s amazing to stand next to this wonderful man,” Hozier said.

Together they sang “Illinois Blues,” a Skip James original from early last century. Fingerpicking in a trance blues style, both players traded vocals with no other accompaniment. Later in the set, Hozier used that style for a song from a completely different era: “1 Thing,” the 2005 hit from R&B singer Amerie.

A few minutes later, he took his crowd to church, but before that, he earned a resounding “Amen.”