By necessity, much of what is heard during a Twenty One Pilots performance is prerecorded. In the studio, Tyler Joseph, the duo’s singer and songwriter, contributes multiple instruments. Sounds are stitched and layered in a way that would require a sizable ensemble to replicate live onstage.

But Joseph and his percussionist partner, Josh Dun, still tour as a duo. So the challenge, especially now that they have graduated to arena headlining status, is how to animate a full show when only some of it is actually "live."

At a sold-out Smoothie King Center on Thursday, Joseph and Dun demonstrated how to create a compelling concert with a hybrid of live and prerecorded music. A smart, contemporary visual presentation, unflagging enthusiasm, and obvious empathy and respect for their audience all played a part.

For two hours, Dun and Joseph cavorted against a backdrop of dazzling LED screens augmented by blasts of smoke and a willingness to toy with arena rock convention. That effort began even before the band arrived onstage. Instead of the arena's normal house lights being on, red lights cast an eerie pall. Instead of a hit parade of other bands' songs played at top volume, the "warm-up music" consisted of an unsettling, droning hum. 

And rather than advertise their faces, Joseph and Dun performed the first handful of songs in ski masks. The masks, and the color red, are primary elements of the strong visual aesthetic built around Twenty One Pilots' million-selling 2015 album "Blurryface" and the fictional character of its title. 

The ski masks also served a practical purpose. Early in the show, the person presumed to be Joseph seemingly disappeared from under a tarp at his piano, only to reappear instantly in section 301, in the arena's upper deck. Obviously, the masked person at the piano had been an impostor. 

Dun's drum solo, that most well-trod of arena rock traditions, was cleverly reinvented as a drum battle with a pre-taped video version of himself. The real and video drummers eyed each other, took turns one-upping each other, and played in tandem. 

Dun spent much of the night shirtless; his athleticism was obvious even before his back-flip off a piano during "Holding On to You." Joseph, in between playing bass, piano and ukulele, made a series of impressive leaps of his own. 

"Blurryface" ranges across the stylistic map but holds together. So, too, the show. Some songs evoked the '80s synth-pop duo Pet Shop Boys. Others called to mind Keane and Spoon, or the Ben Folds Five. Elsewhere, as in "Lane Boy," they tapped into dancehall reggae. Hip-hop was almost always close at hand, as were elements of electronic dance music.

From the opening riffage of "Heavydirtysoul" through such melodically solid sound collages as "Tear in My Heart" and "Stressed Out," they had credible songs to support the showmanship. 

And neither were they opposed to having some unabashed fun. Opening acts Jon Bellion and Judah & the Lion returned to boost four well-rehearsed covers: Chumbawamba's "Tubthumping," Blackstreet's "No Diggity," the Black Eyed Peas' "Where Is the Love" and House of Pain's exuberant "Jump Around." On a more serious note, Joseph and Dun handled My Chemical Romance's "Cancer" themselves.

Several weeks ago at the same venue, the Red Hot Chili Peppers had clearly crossed over into the classic rock demographic. Twenty One Pilots, by contrast, came across as decidedly of-the-moment, and not just because the capacity crowd skewed young. That crowd responded as if Twenty One Pilots was not just a band, but a band to believe in. 

As Joseph and Dun hustled to a satellite stage near the back of the arena floor, footage of the duo from 2011 flashed onscreen. Just six years ago, they were playing backyard parties and changing a shredded tire on their equipment trailer themselves.

Now they can come to New Orleans, a city they haven't played since the 2014 Voodoo Experience in City Park, and sell 12,500-plus tickets. Joseph expressed their gratitude often and made an extra effort to engage fans in the upper level.

Late in the show, he climbed atop a column at the back of the floor during "Car Radio," then ran off into the bowels of the arena, presumably to return for an encore. But as the minutes ticked by, the crowd grew restless, quiet and confused. Was the show over? Was this another twist on arena rock cliche, taken too far?

Finally Dun and Joseph reappeared on the main stage. Unlike the members of a Japanese band they toured with years ago, Joseph said, they had not received a quick massage before the encore. Instead, they were waiting for a technical problem to be corrected. 

At recent stops on the Emotional Roadshow Tour, the encore has consisted of two songs: "Goner," followed by "Trees." But with the 11 p.m. hour approaching, they skipped "Goner" and went directly into "Trees," starting quietly, with Joseph nursing a sedate electric keyboard figure. Once the big chorus kicked in, the party was on. Joseph and Dun surfed atop platforms held aloft by members of the crowd while whacking drums, a trick borrowed from the like-minded New Orleans modern rock band Mutemath, with whom Twenty One Pilots has toured. It reinforced the camaraderie with the crowd.

When he first returned after the long delay, Joseph asked, "We didn't lose you, did we?"

They had, only to immediately win them back.

Follow Keith Spera on Twitter, @KeithSpera.

Keith Spera writes about music, culture and his kids.