When Chris Martin and Jonny Buckland were freshmen at University College London putting together their rock band in 1996, do you think they dreamed of performing in stadiums around the world, dating American actresses and standing at midfield at halftime of the Super Bowl?

Even if they had not an inkling, they've accomplished all of that with Coldplay — and then some.

The biggest rock band to emerge in this century, Coldplay seemed on top of the world Saturday night in front of a full house at U.S. Bank Stadium. Frontman Martin danced like a dork down a long runway, an American flag tucked in his multicolored belt. Fireworks exploded, confetti rained and colorful LED bracelets on the wrists of 45,000 fans blinked in time to the music.

It's hard to argue with Martin's earnestness. Even if some of Coldplay's biggest hits are mellow and often melancholy ballads, he's all about optimism, uplift and plain old fun in concert. He made his plug for world peace, acknowledging conflicts in Korea, Venezuela and elsewhere. He never got preachy or long-winded. And he often got local in his conversation.

Martin gave three shout-outs to the Vikings, saying he hopes they'll win the Super Bowl. He acknowledged Prince three times — referring to him in an ad-libbed lyric to "God Put a Smile Upon Your Face," singing a few lines from the Purple One's "Raspberry Beret" at the end of "The Scientist" and mentioning that Coldplay had played in the club (the name First Avenue eluded him for a second) where Prince filmed "Purple Rain."

Martin always seems eager to please. Maybe too eager. The frequent flaunting of an American flag (including setting it on the stage and kissing it at show's end) seemed a bit much. As did using confetti on five different songs and telling two jokes about One Direction, a group that went on hiatus about the time Coldplay started this tour in March 2016. (A poke at Justin Bieber might have seemed more apropos, since he did cancel his concert that had been set for U.S. Bank Stadium next week.)

Of the four stadium concerts (along with Guns N' Roses, Billy Joel and Florida Georgia Line) that have visited Minneapolis in the past three weeks, Coldplay's seemed to be the most dependent on special effects. Balloons, streamers, laser lights, animated videos, fireworks, flamethrowers, two satellite stages — did we mention confetti? — and those cool LED bracelets, a reprise of a gimmick that Coldplay pioneered on its 2012 arena tour.

Musically, it might be challenging for Coldplay to carry a two-hour stadium show sans the spectacle. Their songs are too similar, though the dance-pop vibe of the recent hits "Adventure of a Lifetime" and "Something Just Like This" (a current collaboration with the Chainsmokers that's Coldplay's biggest hit in nine years) added much-needed energy and new textures. And, of course, the crowd perked up during the festive "Viva La Vida," the U2-like "A Head Full of Dreams" and the energetic "Charlie Brown," during which Martin encouraged everyone to put down their cellphones and jump, which caused the stadium's stands to shake.

Martin seemed to play less piano than in previous concerts, choosing instead to work the runway but rarely the sides of the stages the way the guys in Guns N' Roses did. The other three musicians in Coldplay pretty much remained anchored in a compact space at center stage.

Props to Coldplay — or perhaps promoters Live Nation — for draping fabric over the empty seats and glass windows behind the stage. That noticeably improved the heretofore dubious acoustics of U.S. Bank Stadium.

Since Coldplay emerged in 2000 with the hit "Yellow," the British quartet often has been compared to U2, the great Irish band. Martin, guitarist Buckland, bassist Guy Berryman and drummer Will Champion have always had big ambitions and a big sound. But they have lacked an edge, an artfulness, a cool factor and a grand purpose that have been associated with U2. Minnesota music fans will get to make that comparison for themselves because U2 is next up — on Sept. 8 at U.S. Bank Stadium — in this summer of the stadium concert.

Jon.bream@startribune.com

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Twitter: @jonbream