In the nearly 15 years since Fall Out Boy arrived with the emo-friendly “Take This To Your Grave,” their sound has morphed from punk-pop to anthemic rock ideally suited to the arenas the band is packing on its new “Mania” tour.

Incidentally, the tour was scheduled as a support run for their new album (“Mania”) which was due in September, but shortly before its expected arrival, singer Patrick Stump announced the release was delayed until early 2018.

Not that it matters to the quartet’s fans, an impressive array of teens and their parents at Saturday night’s Philips Arena concert. The band’s seemingly growing base of followers is a testament to FOB’s ability to maximize their second act, which began in 2013 after a five-year hiatus on the strength of the wanted-to-hate-it-but-you-couldn’t “My Songs Know What You Did in the Dark (Light Em Up).”

That particular singalong appeared late in FOB’s 90-minute show, a sturdy display of breathless fist-pumpers, ear-popping pyro and floating stages.

 Pete Wentz did most of the chatting with the audience. Photo: Melissa Ruggieri/AJC

Credit: Melissa Ruggieri

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Credit: Melissa Ruggieri

Stump, guitarist Joe Trohman, drummer Andy Hurley and bassist Pete Wentz opened with a volley of energetic thumpers – “The Phoenix,” “Irresistible,” “Hum Hallelujah” and “Sugar, We’re Goin’ Down” – as scenes ranging from gloriously dappled foliage to cascading waves – blanketed the giant video screen behind the otherwise clean stage.

For “Centuries,” which found Stump hitting challenging notes with gusto, images of NFL players kneeling and Muhammad Ali boxing served as the visual backdrop.

A triangular platform of lights beamed down a rainbow of colors as the guys wandered from one side of the stage to the other or trotted down the catwalk extending the length of the arena floor.

Wentz, still the focal point as well as the member most likely to interact with the crowd, has been criticized for looking bored onstage. But most of FOB’s songs contain similar sauntering bass lines, so that’s what Wentz does when he plays - he nonchalantly strolls in his artfully ripped black pants.

No one can accuse FOB of slacking off during the walloping “Save Rock And Roll,” during which Stump’s melodic piano work contrasted the thumping backbeat from Hurley, dressed only in shorts and tattoos. Stump even credibly aped Elton John’s distinctive vocal style near the song’s end (John appears on the recorded version) before heading into another jaunty piano rocker, the new “The Last of the Real Ones.”

Fans hitting another date on the tour, which runs a couple of more weeks in the U.S., then picks up in 2018 in Europe and Australia, can be assured that any seat is a good one.

An intricate drum solo from Hurley introduced the B-stage segment of the performance, which included the foursome divided between two rising mini-stages at the back of the venue, where they could safely (they were tethered) thrill the rest of the crowd.

Although Wentz and Stump still looked a tad apprehensive as their stage escalated higher, the band still tautly delivered “Dance, Dance,” “Expensive Mistakes” and “Thnks fr th Mmrs.”

Although this “Mania” tour isn’t supporting the intended release, FOB provided an impressive retrospective, including the return of the fan-favorite llamas (to crack wise on video and shoot T-shirt cannons into the live audience), their middle-finger missive (“I Don’t Care”) and their famous movie star salute (“Uma Thurman”).

Given the successful run of the band the past few years, it seems possible that “Mania” might mark the beginning of another break. If so, they’ve sated fans in style.

 Jaden Smith displayed a decent singing voice and pedestrian rap skills. Photo: Melissa Ruggieri/AJC

Credit: Melissa Ruggieri

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Credit: Melissa Ruggieri

Opening the Atlanta concert was Jaden Smith (son of Will and Jada Pinkett) and Blackbear.

Smith alternately rapped and sang – his signing is decent, his rapping pedestrian – as he restlessly paced and high-stepped across the stage. Performing to a pre-recorded tracks and in front of a massive video screen, he moonwalked (quite well) during “Icon” and kept his lovelorn heart shrouded in the darkness of the stage for “Fallen.”

Blackbear – aka Matthew Musto from Los Angeles – employed a four-piece band, including a saxophonist, to present his music, sort of a mix of Mike Posner and Jason Mraz with elements of rap, reggae and pop.

Standing atop a video screen wrapped platform or utilizing the FOB catwalk, Blackbear engaged the crowd with stories (he recorded his 2014 platinum-selling hit “idfc” on a $300 microphone in his bedroom) and a voice that ranged from non-descript pop-rapper (he also co-wrote Justin Bieber’s “Boyfriend”) to interesting falsetto (“Make Daddy Proud”).

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