Imagine Dragons rock SPAC

PHOTOGRAPHER: Erica Miller

Guitarist Wayne Sermon of Imagine Dragons performs during a sold out concert at SPAC on Friday.

Imagine Dragons — one of the biggest pop-rock bands in America right now — didn’t have trouble selling out the Saratoga Performing Arts Center on Friday night. Tickets were gone long before the Las Vegas band took the stage on a beautiful night, and the venue warned non-ticket-holders to stay home.

The crowd, filled mostly with families — parents towing teens and pre-teens or themselves being towed — thrilled to the group’s extravagant pop hits, which rained down on the crowd like the paper confetti shot from cannons inside the amphitheater.

Plumes of smoke shot up from the stage shortly after 9:15 p.m., as frontman Dan Reynolds, guitarist Wayne Sermon, bassist Ben McKee and drummer Daniel Platzman appeared shrouded in fog behind a riser, all banging on percussion for a dramatic start to the dub-heavy, apocalyptic “Radioactive.”

“Thank you for taking part in music today, which is the only thing that stops us from being divided by politics, by religion … Music unites us,” Reynolds said before “It’s Time,” a song with shuffling beats, twinkly synthesizer and soaring vocals that got the crowd clapping along. A barrage of red and purple lights then kicked off the adrenaline-fueled “Whatever It Takes,” from the group’s latest album, “Evolve.”

Imagine Dragons is a pop band flirting with a multitude of modern trends, and the show had a little bit of everything, from the strange, crunching cabaret of “Yesterday” to the smooth electro-synth of “Shots” and “Start Over.” There were angsty ballads (“Next to Me”) and bombastic songs like “I Don’t Know Why” and “Mouth of the River” that combined sleek ’80s synthesizer and anthemic choruses with industrial, clacking beats.

Shirtless frontman Dan Reynolds was the visual focal point on stage — his chiseled, muscular body its own set piece. He may not be the best vocalist, but he’s relentlessly energetic as he works the stage. It was hard not to spend at least part of the night admiring his rigorous workout routine.

The 30-year-old Reynolds has a new documentary out on HBO called “Believer” about balancing his religious beliefs as a Mormon with an awareness of what LGBTQ youth face in the community. Many of his songs were suffused with positive messages. He preached the importance of self-love on “I’ll Make It Up to You,” lambasted greed on “Gold” and spoke about the importance of not stigmatizing depression before “Demons.”

During a mini-set on a B-stage set up between the amphitheater and lawn, the band offered three set highlights — “Born to Be Yours,” “Bleeding Out” and “I Bet My Life.” They closed with a rallying cluster of fan-favorite songs, including “Thunder,” “On Top of the World” and “Believer,” as white balloons dropped from the ceiling.

It’s hard to believe opener Grace VanderWaal is only 14 years old. The singer-songwriter, who accompanies herself on ukulele, won the NBC show “America’s Got Talent” at the age of 12. She demonstrated a truly precocious poise and talent on “City Song,” “So Much More than This,” “Moonlight” and “Clearly,” her re-imagination of the 1970s reggae-soul tune “I Can See Clearly Now.”