As they lined up in Government Plaza two blocks away from the first Final Four concert at the Armory in downtown Minneapolis — three hours before the Chainsmokers’ 9:30 p.m. showtime — Amy and Tommy Ng wondered if the free tickets they scored online were worth anything.

“It’s not logical to advertise it as a free show for everyone, and then hold it in a venue as small as the Armory,” said Amy, of Minneapolis, as she gazed at thousands of other mostly local fans hoping to use their “tickets” before the room hit capacity.

Friday night’s show was the first of three in the March Madness Music Series, which continues Saturday with the newly reunited Jonas Brothers and culminates Sunday with “American Idol” star and Top 40 hitmaker Katy Perry.

In other Final Four host cities, these concerts were held as free outdoor festivals open to everyone. Organizers in Minneapolis moved them indoors to the 8,300-person Armory and would not say how many tickets were made available to the public, who had to sign up and provide personal info via an NCAA website for the slim chance at entry.

“It is disappointing to hear about free shows with artists as big as Katy Perry and the Jonas Brothers and find out they are not entirely open to everyone,” said Julia Bjorke, a 22-year-old fan from St. Cloud hoping to make the “Jo Bros.”

Friday’s show actually was the least-hottest ticket of the three nights. A Los Angeles DJ/production duo that has scored major hits with “Closer” and “Something Just Like This,” the Chainsmokers aren’t nearly as big a deal in concert without the mega-celeb singers featured on those songs, Halsey and Chris Martin.

Banjo-punky Nashville band Judah & the Lion opened the show at 8 p.m. while many fans were still in line outside, soon to finally be turned away. The crowd inside appeared to be maybe one-quarter out-of-towners, many also with tickets to the games. With the matchups not starting till Saturday afternoon, the concert served as their welcoming party.

“There’s so much going on downtown, this just seems like it’s part of the overall experience,” said Randy Fife, in town with a group from Lansing, Mich., all of whom bought tickets even before the Michigan State team upset Duke last week to make the final cut.

As was the case during last year’s Super Bowl parties in the same location, the Armory was glitzed up with extra lights and giant video screens. Each of the competing Final Four teams’ logos were emblazoned small on the venue’s back wall, obscured by dozens of concert sponsor AT&T’s insignia.

Every logo in the room was blurred once the Chainsmokers hit the stage and proceeded to hit their pyro and smoke-bomb buttons every 30 seconds or so. The duo played a rather straight and hopelessly dull DJ set (hence the need for explosives).

Every few songs, the one vocalizing Chainsmoker, Andrew Taggart, came out from behind their giant DJ table — with about 4 feet of equipment and 15 feet of unneeded space — and sang a few bars before motioning to the crowd to sing the rest, like the new single “Who Do You Love.” It was worse, though, whenever Taggart actually finished singing a song himself. Sometimes the duo just pressed play and piped in their prerecorded vocals like a jukebox.

For the Final Four-goers who did not have to wait in the long lines, though, the Chainsmokers made a worthy warm-up act for the long, festive weekend — at least at these concerts’ prices.

“It’s a sports event, not a rock festival,” said Jared Mathiason, in town from Denver. “Of course it’s going to be a little dopey.”