After hitting the Twin Cities six times in two years following the release of their debut album — from the Triple Rock to TCF Bank Stadium — Imagine Dragons might have been accused of suddenly playing hard to get over the past two years, when they didn’t perform a single Twin Cities show.

The wait ended Monday when the Las Vegas chant-rock band of “Radioactive” hitmaking fame returned to Xcel Energy Center, playing to a capacity crowd of nearly 15,000 fans on a school night.

As suggested by the title of the new album, “Evolve,” the group took a little extra time to grow in the interim. Monday’s concert found the band riding high with another big top 10 hit, “Believer,” and delivering a batch of new songs with a sometimes mellower electronic flavor. There was also a lot of personal drama added into the show, including references to this month’s tragic mass shooting in the band’s hometown.

A sign of how the headliners have grown a little more adventurous, they brought along two acts from the indie world for openers. Illinois rapper K. Flay’s half-hour set with a small band got the crowd riled up early and offered the most topical and provocative songs of the night, peaking with “Blood in the Cut.”

Hyper-energetic and slightly cartoony Los Angeles rockers Grouplove, however, were met with a lot of earplugs and pained winces. Co-leader Christian Zucconi’s penchant for singing way off key — even in the hit “Tongue Tied” — really did hurt, as did their comically spazzy version of the Beastie Boys’ “Sabotage.”

The real downside to having two opening acts were the half-hour changeovers and the fact that the band everyone came to see — including many families with grade-school kids in tow — didn’t go on until 9:35 p.m. and lasted until almost 11:30. Ah well, at least it’s MEA week at school.

Imagine Dragons certainly woke up the crowd when it finally took the stage. The four core band members stood out front side by side under rainbow laser lights to kick off the opening song “I Don’t Know Why.” By song’s end, the stage lit up in full with pyramid laser adornments and a giant patch of video screens overhead.

The rest of the group quickly faded into the backdrop as frontman Dan Reynolds — wearing what looked like a cross between painter’s overalls and MC Hammer pants — ran out onto the thrust stage and took command. He wasted no time getting serious, too, referencing the Las Vegas tragedy before the second song, “It’s Time.”

“There have been so many forces trying to divide us lately; especially in our hometown where we lost so many loved ones,” he said, denouncing “anyone who puts fear into the joy of people listening to music together.”

Later, Reynolds opened up about depression before “Demons,” telling the crowd, “It’s not a weakness. ... Don’t keep it inside.”

Those emotional moments added the personality and depth lacking in prior Dragons shows, which were more all-roar in nature. The band scaled back on what used to be its main gimmick, too, when Reynolds and other members pick up sticks to pound tom drums like a frat party turned tribal.

One thing that hasn’t changed, though, is the repetitiveness of their songs. The choruses in new tunes like the Tears for Fears-flavored “I’ll Make It Up to You,” “Mouth if the River” and “Believer” were repeated so often, fans who hadn’t yet heard the new album could easily sing along by song’s end. One of the better of the “Evolve” tracks, “Yesterday” at least only had the one word for the audience to continually yell out, and had a playful closing-down-the-bar spirit to it.

Many of the band’s biggest songs were saved till the last stretch. The final half-hour that consistently rose in momentum, starting with the not-so-stormy “Thunder,” then the big shout-alongs “I Bet My Life,” “Radioactive” and “Believer.”

Before that came another emotional moment as the band took a small stage at the other end of the arena and played an acoustic version of “I Won’t Back Down,” a tribute to Tom Petty two weeks after the legendary rocker’s death. The resiliency preached in the song rang true with Reynold and his crew, too, who’ve clearly gotten past one-hit-wonder status this year.

They still have a long way to go to command a big crowd with as much electricity as fellow anthemic Top 40 rockers like Coldplay or even Kings of Leon (the latter coming to Xcel Center on Wednesday), but after a two-year wait at least we have confirmation Imagine Dragons are indeed evolving.

Here’s Imagine Dragons’ set list from Monday:

 

I Don’t Know Why

It’s Time

Gold

Whaterever It Takes

I’ll Make It Up to You

Mouth of the River

Yesterday

Start Over

Demons

Rise Up

I’m So Sorry

On Top of the World

I Won’t Back Down (Tom Petty cover)

Bleeding Out

Dream

Thunder

I Bet My Life

Radioactive

Walking the Wire

 

Believer