As they arrived at a festival that just three months ago was in danger of being called off for a second year in a row, fans at the Twin Cities Summer Jam in Shakopee on Friday appeared unusually happy just to be worrying about the usual old concerns.

You know, things like heat advisories, long beer lines, port-o-john cleanliness and horse droppings.

"I'm more worried about stepping in something than I am picking up the virus," Curtis Hanson of Inver Grove Heights cracked as he walked toward the Summer Jam stage in the middle of Canterbury Park's horse track.

Still aiming to launch the Twin Cities' biggest multi­day music festival — a goal set in its inaugural year, 2019 — Summer Jam organizers faced the similarly daunting task of being one of the biggest shows in town since Minnesota's COVID lockdown started winding down in May.

About 13,000 mask-eschewing fans took to Canterbury's inner field Friday when Carrie Underwood topped off the bill, sandwiched on the three-day schedule between Thursday's headliners Lynyrd Skynyrd and Saturday's finisher the Zac Brown Band.

The dominance of country acts in this weekend's lineup — a contrast to 2019's with Aerosmith, Pitbull, REO Speedwagon and Soul Asylum alongside Tim McGraw and Rascal Flatts — was one of several facets of Summer Jam's second year partly instigated by the uncertainty around COVID-19.

"Most of the rock acts still weren't sure if they'd be touring this year," Summer Jam CEO Jerry Braam explained backstage Friday.

Braam said both his team and Canterbury's staff also had a little trouble finding enough workers to manage the show, a problem throughout the service industry post-pandemic.

Given that it's been less than three months since mask mandates and crowd-size limits were lifted in Minnesota, Braam sounded happy to have to worry about crowd control at all.

"I'm as happy for these people in the crowd as I am for everyone putting on events like ours," he said.

In the end, beer lines weren't much of a problem, thanks to the Summer Jam's sprawling setup, with two stages spread out across Canterbury's flat, grassy inner field. Ample concession tents and many tiered viewing areas were laid out between the stages (general admission, Gold Circle VIP, reserved VIP, etc., all priced from $100 to $300 per day).

One glaring glitch from the first year — an oversized VIP area that left a large vacant space in front of the stage — was fixed, as were traffic-flow problems cited by attendees from 2019.

"It seems like a great improvement over the first year," said Jackie Staricha of Blaine, attending the festival again with her mother-in-law in matching Underwood T-shirts. Her dad had gone the previous night.

"He loves [Skynyrd] and all the old rock stuff," she said.

Also traceable to COVID uncertainty, this weekend's Summer Jam lineups are relatively light on the number of performers.

Unlike most festivals where music typically runs nonstop, there were hourlong gaps on the main stage between openers Blanco Brown and Brett Young. And only two acts performed on the smaller, K102-sponsored second stage, locals Anthony Daniels and the Jake Nelson Band.

No doubt sensing the Friday night vibe, Underwood left out the Sunday morning songs from her new gospel album, "My Savior." Her 90-minute set instead boasted many of her rowdiest favorites, including openers "Church Bells" and "Southbound," as well as "Little Toy Guns" and "Blown Away." The latter two showed the "American Idol" vet's versatile if sometimes showy voice in strong form after just a handful of gigs since lockdown.

"I love singing songs about Jesus," Underwood said after the bluesy, sax-ridden "Drinking Alone" mid-set. "I also like singing songs where somebody kills somebody."

Friday's heat was lethal enough for the Oklahoma-raised singer to regret her all-black wardrobe choice: "Take bets how long this jacket is going to stay on," she said (it lasted five songs). "There may come a point it needs to stay on to hide the sweat."

The party vibe turned serious in Brown's main-stage set, when the Atlanta singer — a rare Black voice in country music — sang some of the social-justice anthem "A Change Is Gonna Come." He also talked about surviving a motorcycle accident last year that left him temporarily unable to walk.

"We all have struggles and obstacles we have to climb over," said Brown, who moved all around the large Summer Jam stage with apparent ease.

When he finally followed Brown to the stage, fellow Californian Young also let fans in on momentous personal news: He was still wearing a bracelet from the hospital where his second child was born Wednesday.

"So I'm very happy right now," he said near the start of a warmly received set of poppy, lovelorn songs, including "In Case You Didn't Know."

Young certainly wasn't alone in those happy vibes.

"Just being able to get out and breathe in the air and feel the music is wonderful," said first-time Summer Jam attendee Kim Tatman of Minneapolis.

Her counterpart Dan Schaefer added, "I think after [COVID], a festival like this that offers different music to choose from and brings a lot of people together is going to do well."

Chris Riemenschneider • 612-673-4658