There's a car on fire, onstage. The singer disappears, then reappears in the upper deck. The drummer plays directly atop fans on the floor, his kit on a platform held aloft by their arms. The crowd sings along, to almost everything. Those were just a few of the sights and sounds on Sunday evening at the Erwin Center with the eclectic and electrifying duo Twenty One Pilots.

Launched 10 years ago by singer, songwriter and multi-instrumentalist Tyler Joseph, the Ohio outfit is one of popular music's most entertaining live acts of the moment, despite consisting only of Joseph and drummer Josh Dun. There's clearly a lot more to this show than just the two of them: Their crew, which they thanked near the end of the night, has a lot to do with the tricks and treats of their arena-sized spectacle.

But at the core are Joseph's songs, which as a whole are impossible to categorize but usually are so catchy that it's not surprising they've topped Billboard charts, gone platinum and won a Grammy. Twenty One Pilots are pretty good poster children for the theory of a post-genre era in pop music: They mix bombastic power-rock, rapid-fire hip-hop, intimate piano balladry, ukulele-strummed indie-folk, apocalyptic lyricism, anthemic electronica and more into a sound that enamors enough fans to fully pack Austin's largest indoor venue.

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Major hits "Stressed Out" (a 2017 Grammy winner for Best Pop Duo/Group Performance) and "Heathens" (from the 2016 "Suicide Squad" soundtrack) came early, much to the delight of an audience that got antsy during a surprisingly lengthy gap of more than 45 minutes between opening act Bear Hands' half-hour set and Twenty One Pilots' arrival onstage. "Jumpsuit" and "Levitate" from last year's album "Trench" got the duo off to a hot start — literally, as the primary set prop when they first appeared was a late-20th-century sedan engulfed in flames.

Their 23-song set included all 14 tracks from "Trench," an intriguing move for a band with a fairly deep well of hits to draw from. They reached back to 2011's "Holding On to You," their first charting single, and worked in several favorites from their 2015 mass-breakthrough album "Blurryface," including "Ride," "Fairly Local" and "We Don't Believe What's on TV."

Midset, a scaffold was lowered from the ceiling to create a runway for Tyler to cross over to a smaller stage at the other side of the arena. Dun soon joined him there as they played some of the evening's lower-key but most musically rich songs, including "Smithereens," "Neon Gravestones" and "Bandito" from the "Trench" album.

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Tyler often played piano, sometimes switched to bass and occasionally picked up a ukulele, when he wasn't simply prowling the stage with a mic and coaxing the crowd into a frenzy with bursts of dizzying rap verses that often led into catchy pop choruses. Both he and Dun changed outfits frequently, sometimes obscuring their faces with bandanas, ski masks or hoodies.

Nearly everyone in the Erwin Center stood for the duo's entire two-hour performance, saving some of their most energetic call-and-response singing and pogo-jumping till the end. On both "Car Radio" and the show-closing "Trees" (from 2011's "Regional at Best"), you could feel the stands shaking from the force of everyone jumping in unison.

Opening act Bear Hands got just 30 minutes to warm the crowd up before that long wait till the headliner. A four-piece from Brooklyn, they served up modern-rock songs that had intriguing rhythms but often lacked strong melodic hooks. Getting this opening slot was clearly a huge coup, but they might best be appreciated at this stage of their career at more intimate venues a few blocks south on Red River Street such as Barracuda or the Mohawk.