When it comes to Willie Nelson’s Fourth of July Picnic, it seems you can never get enough angels flying too close to the ground.

Near the end of her immaculate hourlong sunset performance, Alison Krauss began singing the song that some consider Nelson’s best. "Angel Flying Too Close to the Ground" is perfect for the Nashville songbird: When her soaring soprano voice lifted its final stanza to the heavens, it felt like nothing at this year’s Picnic possibly could touch that moment.

And maybe nothing did. But about four hours of the marathon event at Circuit of the Americas remained at that point, with Nathaniel Rateliff & the Night Sweats, Luke Combs and finally Willie himself — along with a short fireworks display — taking us right up to midnight. The 12-hour event started a tad behind but quickly got back on track and stayed on schedule the rest of the way.

Nelson, no doubt appreciative of Krauss’ version yet undeterred, gave us “Angel Flying Too Close to the Ground” again about halfway through his own hourlong set. Willie's half-spoken, half-sung recitation instilled the bittersweet words with a gravitas only a song’s author can deliver. He carried the rare beauty of its melody on Trigger, the trusted acoustic guitar that has accompanied Nelson through Picnics thick and thin since they began in the early 1970s.

Much of Willie’s performance on this night was like that. He sounded great in the warm night air — temperatures in the 90s with a heat index of 100 cooled to 79 degrees with a light breeze by the end — but his vocals were more conversational than mellifluous, which made the living legend feel personable. When a greater vocal heft was needed, the crowd was more than happy to sing along on the choruses of “Beer for My Horses,” “On the Road Again” and other favorites.

A surprise in the set’s home stretch was the inclusion of three songs from Nelson’s new album, “Ride Me Back Home.” Unlike most artists, who typically tour to support their new material, Willie’s usually content with trotting out the tried and true. But clearly he has connected deeply with the late Guy Clark’s “My Favorite Picture of You,” and it sounded wonderful on this night, with sister Bobbie Nelson’s piano filling in the radiant colors of its faded-Polaroid theme.

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To work in the new album’s material, Willie trimmed not the seemingly more disposable Hank Williams medley he often plays, but the medley of his own all-time classics. If you’ve heard that “Crazy”/“Night Life”/“Funny How Time Slips Away” trilogy many times before, this was no big deal. But any in the crowd who’d never seen him before might have missed its inclusion. That’s pretty much the only down side to writing so many great songs in 86 years of living.

Earlier, North Carolina native Combs proved perhaps the ideal mainstream-country performer to be shoehorned into the Picnic’s pre-Willie time slot. Since the show moved back to the Austin area in 2015, organizers have had mixed results with that placement; Eric Church fared reasonably well, but Brantley Gilbert was a disaster. Picnic planners clearly take an all-things-for-all-people approach, but many contemporary country acts just don’t fit the Willie vibe.

Combs did, in part because he’s exceedingly good-natured and almost impossible to dislike. Churning out chart-toppers such as “Hurricane,” “Beautiful Crazy” and “She Got the Best of Me,” Combs frequently offered heartfelt introductions to tuneful numbers that had his fans singing along. He’s a bit of a humble-bragger, slipping in references to his five No. 1 hits between soliloquies about how grateful he is. But he clearly meant it when he marveled at the opportunity to share a Picnic stage with Willie and “so many people I have looked up to for my entire life.”

Further broadening the Picnic’s big-tent approach were Nathaniel Rateliff & the Night Sweats, a hard-working Colorado soul band that bridged the gap between dusk and the 9:30 p.m. fireworks display. There’s a clear parallel between Rateliff’s outfit and Austinite Kevin Russell’s soul-powered Shinyribs, though the Sweats are less swampy and perhaps more deeply rooted in classic R&B. A three-piece horn section propelled Rateliff’s guitar-and-vocal exuberance, keeping the crowd upbeat at a point when folks who’d been there all day probably needed the energy boost.

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Early arrivals caught four hours of music on the adjacent plaza stage before action shifted to the Austin360 Amphitheater at 4 p.m. Willie’s beloved three-named old pals — Ray Wylie Hubbard, Billy Joe Shaver and David Allan Coe — all got their turns in, though Shaver’s four-song set felt far too short for the best songwriter at the Picnic not named Willie Nelson.

Great singers also had their moments on the plaza stage, with 75-year-old Gene Watson and 84-year-old Johnny Bush both delivering fine performances. Bush closed with the song he wrote that has forever been Willie’s concert opener, “Whiskey River.” Sure enough, we’d hear it again about 9 hours later, over on the big stage.

The stage-transition part of the afternoon included a half-hour on the plaza stage from Texas troubadour Hayes Carll, whose wistful song “American Dream” from his latest album was a good fit for the Independence Day of a polarized nation. Meanwhile, the amphitheater stage got up and running with a U.S. visitor, Canada’s Colter Wall, a rising young talent whose classic-country voice fascinatingly sounds twice as old as he is.

Steve Earle & the Dukes followed Wall with a 40-minute set that included five songs from his new Guy Clark tribute album: “Dublin Blues,” “Texas 1947,” “Rita Ballou,” “Desperados Waiting for a Train” and “L.A. Freeway.” Earle could have played nothing but Clark and still shine like diamonds, but he probably figured some of his fans at the Picnic also wanted to hear his own hits “Guitar Town” and “Copperhead Road,” so he worked those in, too.

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We didn’t get any politics from Earle on the Fourth of July, somewhat surprising given he’s one of the most outspoken artists in contemporary popular music. Shaver steered around such issues earlier in the day, suggesting that “politics ain’t got a lot to do with it. God’s in control of all this.”

The acoustic duo Folk Uke — featuring Willie’s daughter Amy Nelson on guitar and Cathy Guthrie (daughter of Arlo) on ukulele — followed Earle on the big stage with a short set that included a pointed number directed at the president, titled “You Must Have a Small One (to Act Like Such a Big One).” Amy also voiced her support for immigrant women being held at a detention center in the Austin suburb of Taylor and lauded the efforts of Texas organization Grassroots Leadership.

It was the next performer, the spectacular singer Jamey Johnson, who cut closest to the bone of the American spirit — with help from Cathy Guthrie’s grandfather. When Johnson launched into a reverential version of Woody Guthrie’s “This Land Is Your Land,” many in the crowd stood and some removed their hats, giving Guthrie’s now nearly 80-year-old song national anthem-like respect. In the end, no speeches were needed: Johnson’s voice, and the song’s uplifting message of freedom, carried the day.

LISTEN — American-Statesman writer Peter Blackstock talks about Willie's Picnic on Austin360 Radio: