Attendees of Willie Nelson’s Fourth of July Picnic relax between performances at the Circuit of the Americas on Saturday, July 4, 2015.
Photo by Shelby Tauber/American-Statesman

For a solid 10 hours, everything went off without a hitch Saturday at the first Picnic at the Racetrack. Returning to Austin for the first time in five years, Willie Nelson’s Fourth of July Picnic booked a remarkably strong lineup at Circuit of the Americas, and around 20,000 fans turned out to join in the celebration.

After the sun went down, though, everything went a little haywire. The Picnic crew had made it through 20 acts without ever falling more than 10 minutes behind, admirably shuffling short sets by the first 10 performers from 11:15 a.m. to just past 3 p.m. on a makeshift stage in the venue’s Grand Plaza. A wide grass lawn offered plenty of room for standing or sitting, plus quite a few picnic tables in back.

After 3 p.m., sets began rotating between the plaza and the main Austin360 Amphitheater stage. Things stayed on track for another six hours, as legends such as Kris Kristofferson, Leon Russell and Billy Joe Shaver split time with a superb cast of rising stars including Sturgill Simpson, Jason Isbell and Kacey Musgraves.

It was after Musgraves’ terrific 8 p.m. set that the back-and-forth shuffle between the two stages ceased, and the crew couldn’t keep up with the pace the rest of the way. A scheduled 15-minute reset on the main stage between Musgraves and Merle Haggard stretched to almost 40 minutes. By the time a scheduled short fireworks display followed Haggard’s set, the show was a full hour behind.

Adding to the down side was the necessity of sitting through an hour of Eric Church before Willie and his family band brought the show to its natural apex. Context is everything: When Church played the iHeartRadio Country Festival at the Erwin Center last year, he stood out as one of the night’s better acts, sounding about as good as mainstream country radio has to offer. But set against the likes of the Picnic’s otherwise brilliantly assembled lineup of songwriters, his songs about drinkin’ a cold one, drinkin’ a product-placement brand of whiskey and just drinkin’ the drink in his hand revealed him to be an empty suit.

For brief moments, he tried to break out, such as when he prefaced his quasi-anthem “Springsteen” with a heartfelt run through the first verse and chorus of Robert Earl Keen’s “Corpus Christi Bay” that begged for a full rendition. And he chose wisely in his set closer with The Band’s “The Weight,” inviting late-afternoon main stage highlight Chris Stapleton back out to sing one of the verses.

It was with Stapleton’s 4:40 p.m. set that the Picnic fully hit its stride. Kris Kristofferson had played the first set on the Amphitheater stage immediately before, performing solo with no fanfare but setting a proper tone that if you’re going to play Willie’s Picnic, you better bring along some top-shelf original songs. Stapleton, who’s written a lot of hits for other artists but is just now getting his shot in the spotlight with his acclaimed album “Traveler,” proved up to the task, shining with a soulful backing band that brought out the drama of songs such as “Nobody to Blame” and the record’s title track.

Next on the big stage was Sturgill Simpson, whose recent sold-out Stubb’s shows and “Austin City Limits” taping showcased a talent whose 2014 breakthrough album “Metamodern Sounds in Country Music” brilliantly synthesizes country and psychedelia. Simpson mostly avoided the latter on this day, choosing instead to delve more into his bluegrass roots — “I know we’re in Texas, but I’m from Kentucky!” he explained — in a 40-minute set that spotlighted his full-throated vocals and his band’s hot picking.

From a pure songwriting perspective, no one beat the main stage’s next performer, reigning Americana Music Association Artist of the Year Jason Isbell. As much as his 2013 album “Southeastern” sparked a career peak, it’s his upcoming “Something More Than Free,” due July 17, that stands to launch him into another league, judging from Saturday’s renditions of the album’s passionate title track and the spectacular first single, “24 Frames.” Isbell also reached back to his Drive-By Truckers days for “Outfit” and “Decoration Day,” both of which offered fitting alternate-view perspectives on the Independence Day atmosphere.

Amid this auspicious stretch of main stage up-and-comers was a strong anchor of sets from Picnic faithful on the smaller stage. In succession, the swelling plaza crowd was treated to the classic honky-tonk of Johnny Bush, the outlaw mysticism of Billy Joe Shaver, the piano Hank-and-Stones shuffle of Leon Russell and the western swing revival of Asleep at the Wheel. Closing out the Plaza Stage run just before sundown was Jamey Johnson, who smartly kept the backing low-key so his vocals could shine on stirring covers of Woody Guthrie’s “This Land Is Your Land” and George Jones’ “He Stopped Loving Her Today.”

That was a perfect segue into the big-stage performance of Musgraves, who’s all the rage even in mainstream country circles these days but is smart enough not to lower herself to that common denominator. Dressed for the part in a spangly starred white outfit that played off her new album’s “Pageant Material” title, Musgraves proved fully worthy of a Picnic headlining slot with smart songs such as “Mama’s Broken Heart” and “Step Off” that pointedly refrained from Nashville bombast-and-cliche. And when she got to her smash hit “Follow Your Arrow,” it was a perfect fit for Willie’s Picnic, with its sly little exhortation in the chorus to “roll up a joint.”

It was all downhill from there, with the way-too-long pause before Haggard’s decent but unremarkable set sparked primarily by Willie’s cameo at the end for Townes Van Zandt’s “Pancho & Lefty” and the novel single “It’s All Going to Pot” from their chart-topping new duo album. The fireworks, and Church’s lack thereof, chased some of the crowd home before Willie finally took the stage at 12:23 a.m. on July 5 – though the vast majority of the crowd did stick around in a heartfelt show of solidarity for their beloved host.

He and his Family Band — pianist Bobbie Nelson, harmonica player Mickey Raphael, bassist Kevin Smith and drummer/percussionists Paul and Billy English — rewarded them with about an hour of trademark Willie, from the obligatory “Whiskey River” and “On the Road Again” to medleys of his own timeless classics (“Funny How Time Slips Away”/“Crazy”/“Night Life”) and those of Hank Williams. Around 1:15 a.m., an official came onstage and apparently obliged them to wrap things up, so Willie invited out performers still on hand backstage including Kristofferson, Johnson and Church for “Will the Circle Be Unbroken” and “I’ll Fly Away” before a finale that he described as “my new gospel song” — “Roll Me Up and Smoke Me When I Die.”

A quick look at early-afternoon highlights, which featured 15-to-20-minute sets from a cross-section of performers:

Three-named Texans Ray Wylie Hubbard and David Allan Coe got the Picnic faithful smiling and dancing with hallmark numbers such as “Screw You, We’re From Texas” and “Take This Job and Shove It,” respectively. A trio of Nelson family acts helped the crowd ease into the heat of the afternoon, with Paula Nelson paying tribute to Waylon Jennings and Mickey Newbury after Raelyn Nelson rocked out on Joan Jett’s “Bad Reputation” and the duo “Folk Uke” (Amy Nelson and Cathy Guthrie, Arlo’s daughter) singing comic songs that were mostly unprintable but quite entertaining. Sirius/XM DJ Dallas Wayne, a fine songwriter in his own right, played two excellent tunes and deserved more time. Armadillo World Headquarters veterans Greezy Wheels played a short but energetic set that helped put the Picnic in historical perspective. And Hudson Moore, Amber Digby and Pauline Reese provided a spark for those just arriving to the Circuit of the Americas grounds before noon.

Despite the late-night scheduling snafu, COTA proved a good spot for the Picnic, though its outrageous concessions prices are a failing grade on an otherwise strong report card. If a family of four spent the full day at the picnic and needed two meals, a couple of snacks, a few beers and sodas, and consistent hydration from bottled water — there are a few water fountains on site, but they’re tucked away — just the cost of those essentials could easily run $200-$300 for the day. With no food or drink allowed in, that amounts to racetrack robbery.

American-Statesman staffer Dave Thomas contributed to this report.