Once upon a time, many, many years ago, there lived soft rock bands like Toto, Mr Mister and REO Speedwagon. These melodic, musically skilled bands were mocked by the cool kids of the time, who listened to Van Halen and Motley Crue. And they were all ridiculed by the really cool kids, who listened to Black Flag, The Minutemen and Sonic Youth.

But it turns out those titans of sensible volume of the past have had the last laugh. Because as Imagine Dragons proved at a nearly full Rogers Arena last night, the soft rockers have won.

Imagine Dragons are a band so soft they make Fleetwood Mac sound like Slayer. Whatever they’re doing though, it’s working. The overnight rise to megastardom. The Grammy Awards. The invitation to toast The Beatles. They’ve come a long way since they headlined the Commodore Ballroom 11 months ago.

The trick, it would appear, is to go with what people already like. That was apparent from their first song, “Fallen,” the first of many readings from the Coldplay textbook of arena anthems. “Tiptoe,” straight after, echoed Joshua Tree-era U2. “Hear Me,” the next song on the set list, could have been lifted directly from fellow Las Vegans The Killers.

Aping the sounds of success is a smart move for any band looking to make it big, but Imagine Dragons’ particular brand of commercial genius lies in their lyricism, where the devoutly religious front man Dan Reynolds (the kind of nice guy who anyone would be happy to let date their sister/daughter), has turned generic self-affirmation into an art form.

“Doesn’t matter if it’s not ok, because it’s who we are,” are the key words from “Who We Are,” followed by the repeated refrain “They say we’re crazy,” an opinion presumably not from anyone who’d listened to their resolutely mild style of rock with no roll. “Now don’t you understand,” he bellowed through “It’s Time,” “I’m never changing who I am.” The cumulative effect was the musical equivalent of a series of inspirational facebook memes.

When not performing a commendable Chris Martin impression, Reynolds was playing his salt-of-the-earth charm for all it was worth. Sometimes it worked.

“I promise you this, there has not been one show we take for granted.”

Sometimes it didn’t.

“This song is about the meaninglessness of money,” he explained by way of introducing “Cha-Ching,” at which point the young man sitting behind your correspondent observed how that was an interesting opinion from a band selling t-shirts in the concourse for $35 a piece.

Although much of Imagine Dragons’ set sounded like soundtracks for car commercials waiting to be filmed, there’s probably a bold band somewhere in there waiting to get out. The entire show finished with a terrific blast of guitar pyrotechnics from Wayne ‘Wing’ Sermon at the end of “Nothing Left To Say.” “Tom Sawyer” by Rush was a brave choice of mid-set cover too, Reynolds fighting to reach the high notes and deserving further commendation for the correct pronunciation, ‘Tom Sawyee.’

“Demons” and “Radioactive,” the climactic hits, were both performed with due earnestness, the latter elongated by one of countless percussion breaks performed on the numerous snare, toms and giant bass drums littered around the stage.

The fact that Imagine Dragons delivered all the rock and roll thrills of a bag of organic quinoa seemed to be besides the point. The new generation of music fans have spoken. And they want their rock soft enough to cuddle. If that’s ok with you? Are you sure? Thank you.

Robert Collins