LOS ANGELES — Jennifer Lopez strode into a soundstage on the Universal Studios lot with the crisp forward momentum of someone you’d hate to disappoint.
Alas, that’s what was about to happen.
Clutching a bedazzled water bottle with her nickname spelled out in rhinestones, the singer-dancer-actor known as J. Lo had arrived at a recent rehearsal for her upcoming arena tour and wanted to know whether a specialized nonstick substance had been applied to the stage overnight. People wearing headsets conferred quietly with one another; eventually, a crew member said he hadn’t been notified in time to allow the four or five hours the stage would need to dry.
“OK, Jen, no sliding today,” the tour’s director told Lopez, whose face crinkled briefly with irritation before smoothing out again. So she couldn’t slide. She could still spin, jump, twirl, shimmy and twerk — all of which she proceeded to do in an assured run through the two-hour song-and-dance spectacle.
Billed as the It’s My Party Tour, the production is meant to mark Lopez’s 50th birthday, which will fall on July 24, just days before the North American tour’s final date in Miami. And if you’re surprised to find a woman in show business happily flouting the industry’s ageist streak, you’re not alone.
“Some of the people I work with are like, ‘Why are you doing this? Now everybody’s out there saying you’re 50,’ ” she said after the rehearsal. “I am 50. But I feel like I’m 28.” With a laugh, she recalled a video clip from the concert in which a young Lopez predicts she’ll be in a wheelchair by this point in her life. “And I’m not. That’s to be celebrated. Just because you know my real age, it doesn’t matter. Can I pull it off?”
J. Lo can still pull it off. More than her physical stamina, though, what her performance really calls attention to is the unlikely musical endurance of this triple-threat entertainer who started out in the early 1990s as a so-called Fly Girl on television’s “In Living Color.” Nobody has seriously doubted Lopez’s abilities as a dancer since then.
But little about her lightweight 1999 debut album, “On the 6,” which followed breakout acting roles in “Selena” and “Out of Sight,” suggested that Lopez would be playing arenas 20 years later.
Yet here she was putting the final touches on a road show stacked with familiar hits from the last two decades — songs that demonstrate her eagerness to adapt (from the slinky dance-pop of “If You Had My Love” to the thumping pop-rap of “Jenny From the Block” to the rowdy Latin trap of last year’s “Dinero”) — along with the charisma necessary to hold them all together.
You wouldn’t call her the world’s strongest singer, as a poorly received Motown tribute at this year’s Grammy Awards made clear. But as a pop star — as a creator of memorable sounds and images — J. Lo has proved surprisingly flexible. Even her old stuff is up for revision: In the new concert, she mashes up her songs with current hits by other acts, including Blueface’s “Thotiana” and Travis Scott’s “Sicko Mode”; for “If You Had My Love,” she cleverly sings over the instrumental track of Drake’s “Teenage Fever,” which sampled Lopez’s song (and is thought to refer to their brief romance).
“I don’t want to be that person who’s like, ‘The music when I was young ... ,’” she said as she rode in a chauffeured Escalade toward the Van Nuys Airport. After finishing the run-through, Lopez had quickly discussed the performance with her team; now she was headed to a private jet that would take her to Miami, where her 11-year-old twins were due to graduate from middle school. “I want to be the person who can appreciate the evolution of everything that’s always happening in the world,” said the singer, who’s recently released Spanish-language singles featuring Bad Bunny and Ozuna, among others.
“It’s almost like falling in love. After being with someone for a long time, you see somebody else and ... “ Lopez trailed off into laughter, an acknowledgment of her tabloid history of relationships with the likes of Ben Affleck, Puff Daddy and Marc Anthony, with whom she had her kids. (In March, Lopez announced she was engaged to Alex Rodriguez, the former New York Yankees star.)
“When you have something that’s new, it’s fun,” she said. “Whether it lasts a long time, that’s another story.”
Lopez’s tour grew out of her residency at Planet Hollywood in Las Vegas, which closed last fall after raking in more than $100 million over nearly three years, according to Billboard. The singer’s longtime manager, Benny Medina, said the idea was to scale up the relatively intimate Vegas gig to suit rooms with 20,000 seats — but without losing what he called the “magical” connection J. Lo created with her audience.
Their success in that regard is debatable; the coziest moment in the new production arrives in an unnecessary rendition of a Sara Bareilles tune. But for all its razzle-dazzle, there is a spontaneity to the show that reminds you there’s a real person up there amid the feathers and sequins. Lopez mostly sings live, which is hardly a given in her part of the pop world.
“Listen, I may drop out here and there, but at the end of the day, they came to hear what you sound like and to feel that energy,” she said. Dressed in stretchy athletic pants and a black warm-up jacket, she rubbed lotion into her hands but stopped when asked if she, like many performers, relies on a prompter onstage.
“There’s no prompter,” she replied in a friendly get-outta-here tone. “I know Marc uses a prompter. I don’t.” She laughed. “Sometimes you do forget your lyrics. You just have a brain fart: ‘Where am I right now? I’ve been out here for two hours. Is it over yet?’ ”
It was startling to hear Lopez use the F-word, which wasn’t at all in keeping with the fashion-icon vibe she puts across in her music videos and on Instagram. But as the car neared the airport, she said one reason people have remained interested in her for so long — even when a given movie or a given record flops — is that they relate to her.
“They know where I come from, and I don’t hide my flaws,” said the artist, who recently wrapped production on the movie “Hustlers” with Cardi B and will start shooting a romantic comedy with Owen Wilson in October. Part of that is our fascination with her roller-coaster romantic life, which she said can be tiresome.
“You’re like, ‘I wanna talk about my movie,’ and they’re like, ‘We’re much more interested in your boyfriend.’ ”
But there’s also something of a fan’s impulse in J. Lo’s savvy musical approach. In her records (and the ones she interpolates in her show), it’s easy to hear what excites her about music; she’s never too cool for the room, which means she’s never outstayed her welcome.
“Are we here?” she asked in a broadly comic British accent as the SUV pulled onto the tarmac, where several planes were idling. “Is ours the one with the four-leaf clover on it?”
From the backseat, one of her dancers who was traveling with her asked, “Do we need the luck?”
“No, we don’t need it,” Lopez replied. “Obviously, we don’t need it.”