When Ella-Yelich O'Connor emerged with her debut album, Pure Heroine, in 2013, the New Zealander known as Lorde was presented as a precocious, mature-beyond-her-years artist, a teenage leader of the pack who had no time for frivolous materialist indulgence.

Instead, on her breakout single "Royals," Lorde declared that she and her friends, several thousand of whom were in attendance and singing along when she played the Wells Fargo Center on Monday night, "crave a different kind of buzz."

That first impression of Lorde as an artist of substance, an impressively composed 16-year-old phenom who updated the confessional singer-songwriter archetype with savvy production skills and a serious sense of purpose, turned out to be accurate. And it also turned her into an international star with an intense following of coming-of-age fellow teens in the market for pop songs that deliver emotional depth along with memorable hooks.

Sudden stardom, however, adds to the Sturm und Drang of youth,  and Lorde had some growing up to do in order to write Melodrama, the follow-up album released nearly four years after  Heroine, that brought her to South Philadelphia on Monday, along with a pair of hand-picked openers in rap duo Run the Jewels and indie songwriter Mitski.

Melodrama is an album about life turning out to be more complicated and heartbreaking and deliriously exciting than it might have first appeared. Produced with Jack Antonoff, who also assisted last year on St. Vincent's Masseduction, it adds sweep and subtlety to Lorde's sound while still tending toward the understatement with which she's most comfortable.

The album confirms that Lorde,  now 21, has staying power, and it deservedly landed on lots of year-end best-of lists. But it didn't achieve the chart-topping success of Pure Heroine, and the Wells Fargo was less than full on Monday. In fact, as with Lana Del Rey's recent show at the South Philly venue, the upper level was closed off and entirely empty. Along with Arcade Fire last year, add Lorde to the list of next-generation pop stars being pushed onto the arena circuit without the ticket-selling firepower to fill the oversize spaces.

Not that that mattered one iota to the singer's assembled fans, who stood throughout her energetic and engaging 20-song set, which pulled from Heroine and Melodrama, and which included a nicely turned cover of Bruce Springsteen's "I'm on Fire," mixed together with her own "400 Lux." The just-for-Philly song selection, on which she was accompanied by an acoustic guitarist from her three-piece band, came in a slot midway through the show that's she's used for covers of Frank Ocean and Kanye West on previous stops.

Lorde's allure has much to do with her authenticity and close connection to her audience. The Melodrama tour presentation made concessions to the need to put on a visually enticing show in such a big space, but it did so in creative ways.

With the musicians in the background, Lorde was accompanied by a squad of female and male dancers whose fluid movements had more to do with interpretive or ballroom dance  than with the militaristic lockstep choreography that marks most pop spectacles.

The inventive stage prop was a glass-walled train car-shaped room that rose and fell above the stage with the dancers in it. It also gave Lorde a place to go for a costume change from the baggy pants and sneakers ensemble she entered in to the flowing green gown that she wore while the dancers lifted her overhead during the Wall of Sound coda to "The Louvre."

The show's upbeat moments were effective, particularly Melodrama's lead single, "Green Light," which Lorde introduced as a song into which she put "all of the joy, all of the pain and pettiness, all of the jealously and craziness," and which ended the pre-encore set with an ecstatic  release of confetti. Ultimate audience bonding was achieved later with the grand finale of "Team," in which the she took to the crowd to press the fresh, singing out, "We're on each other's team."

The real highlights, though, were in the quieter moments that made intimate connections possible. Along with "I'm on Fire," there was a spoken interlude in which Lorde announced, "They told me to talk about sports. I heard about the Eagles and I know about your 76ers," and joked about how she and her bandmates were worrying about catching athlete's foot from showering in sports arena locker rooms on tour.

That comic routine came before the delicate but pointed "Writer in the Dark," a song about how communing with your most authentic self is the essence of art, and how payback can be nasty for wayward lovers in relationships with songwriters. Introducing it, she said that during the making of Melodrama, "I learned a lot about myself. You just have to be who you're supposed to be. The vivid dreamer, the hopeless romantic, the crazy over-reactor blowing up your boyfriend's phone. The writer in the dark."

Lorde isn't a rapper, but she's a lyric-focused songwriter born of a generation raised on hip-hop whose vocal approach is rhythmic as much as melodic. So having a hard-hitting duo like Run the Jewels open for her made more musical sense than you might think.

The biracial team of rappers Killer Mike and El-P came hard with a 45-minute set of songs that explored anger, loss, and brotherhood, delivered with an impressive tag-team attack and booming bass beats that shook the room.

It was a set of many shout-outs, starting with an obligatory "Free Meek Mill," and followed by mentions of Allen Iverson, Randall Cunningham, Mitchell & Ness (the Center City sports apparel store where the duo spent the day shopping), the then-not-yet NCAA men's basketball champion Villanova Wildcats and Brian Koppelman, creator of the Showtime drama Billions, who was in attendance with his daughter.

That last announcement by Mike — last name Render — led to a tribute to and a call for respect as an intro to "Stay Gold." Later, Mike talked about his mother's attempting suicide when he was young and urged anyone in the crowd coping with depression to realize  they're never truly alone. The politically outspoken rapper did not address his criticizing the national school walkout day in an NRA TV interview whose excerpts aired on the day of the March for Our Lives protest last month and for which he has since apologized.

The show started at 7 p.m. sharp with an attention-grabbing nine-song set by Mitski, the Japanese American guitarist and songwriter — last name Miyawaki — who specializes in bristling rock songs that depict the romance of the idealized American dream from the perspective of an outsider. Fronting a four-piece band, Mitski had no trouble projecting throughout the room with her nervy sound. She thanked the headliner for the opening slot and instructed early arrivals to note the spelling of her name on the video screens in case they wanted to google her.