They stood still, basking in the screams for a good 15 seconds. Nick, Joe and Kevin — the Jonas Brothers — had just finished their first song at jam-packed Xcel Energy Center on Monday.

They looked different from 10 years ago, when they last appeared in a Twin Cities arena. The leather jackets and jeans were replaced by brightly colored suits. The shaggy hair was now carefully coifed, with hints of George Michael facial hair. And those infamous purity rings had given way to wedding bands.

Yes, the Jo Bros have grown up. The Disney Channel-launched boy band of the mid-'00s are now adult popsters. And there are thousands of girls — sorry, young women — who have grown with them. But plenty of female tweens and teens turned out at the X, too, thanks to the trio's 2019 comeback album, their first studio project in 10 years, and their first-ever No. 1 song, "Sucker."

Whether you were a new or old fan, the good news is that the Jonas Brothers were more infectiously fun than ever. Some of that was due to a loose and spontaneous acoustic set a half-hour into their performance. The trio journeyed to a satellite stage at the far end of the arena. After singing a new song, the Shawn Mendes-like "Hesitate," on an elevated platform, the brothers came back down to earth.

Joe pointed out that it was not only National Guacamole Day, but also Nick's 27th birthday. Out came a cake, candles and his wife plus several crew members. All 17,000 fans sang "Happy Birthday."

Clearly touched, the usually wooden Nick loosened up for the ensuing crowd request, the Jo Bros oldie "Sorry." Turns out it was co-written by Minneapolis musician John Fields, who produced 2007's "Jonas Brothers" CD and a side project, Nick Jonas & the Administration, and who happened to be in the arena on Monday.

Then it was time for Nick to exercise his solo chops on his 2014 lite-funk hit "Jealous." Joe was up next, doing his dance-happy hit from his group DNCE, "Cake by the Ocean," complete with confetti and flying balloon characters.

Joe, 30, clearly has the best stage presence of the three brothers. He showed rock-star swagger, with loose-limbed dance moves and a sexy way of dragging his microphone stand across the eye-shaped stage.

The often-animated Kevin, 31, always had a guitar strapped around his shoulder — except when he played grand piano on "Comeback," a power ballad that closes the new album, "Happiness Begins."

Material from the new record filled about half of the 100-minute performance. In concert, the songs sound less mechanical than on record. "Rollercoaster," the sparkler-fueled show opener, came across like a Mumford & Sons stomp. An island vibe colored the romantic "Only Human," while "Cool" felt like a Miami Beach breeze. And the finale, "Sucker," suggested Maroon 5 with its high-pitched pop vocals and jittery clap-along rhythm.

But it was the Jo Bros oldies that received the loudest reaction — the singalong "Lovebug" and the long medley that peaked with "Hold On" and "Tonight."

Occasionally throughout the evening, videos depicting actors as the Jonas youngsters were shown as interludes on a giant curved screen. The clips were designed to suggest how their childhood made them dreamers about what might happen when they grow up.

But the look on the faces of the Jonas Brothers basking in the early-show scream-a-thon spoke louder than all the videos combined.

Opening the concert were generic pop wannabe Jordan McGraw, who is the son of TV's Dr. Phil, and eminently likable pop star Bebe Rexha, who has had a steady presence on Top 40 radio for the past six years.