Sabrina, Charli and Chappell are suddenly stars. Why now?

There were lime-green tube tops, lime-green beanies, lime-green hoodies and cowboy hats and sunglasses and at least one lime-green mesh vest like something an especially with-it street paver might wear. But even those not dressed in the glaring color of Charli XCX’s glaring new album, “Brat,” were showing their devotion to the English pop singer this month, shouting along with every word as she performed all 15 of the album’s tracks for a capacity crowd vibrating with excitement at the Shrine Expo Hall in Los Angeles.

“I don’t want to sing this one — I just want to hear you sing it,” she said before the beat of “B2B” kicked in at a pulverizing volume, and nearly every person in the room seemed overjoyed to oblige her.

With tickets going for hundreds of dollars over face value on the secondary market, this recent sold-out concert was a convocation of the ultra-loyal Charli XCX fans — Charli’s Angels, many call themselves — who’ve helped maintain her cult-fave status over the decade and change since she emerged in the early 2010s with appearances on hits like Icona Pop’s “I Love It,” which she co-wrote, and her own solo debut, “True Romance.” For almost Charli’s entire career, her tuneful yet edgy brand of electronic pop has held a distinct connoisseur’s appeal — a kind of if-you-know-you-know energy that’s endeared her only more deeply to her core following.

Yet signs keep mounting that the wider world is starting to pay attention.

“Brat,” Charli’s sixth studio LP, debuted last week at No. 3 on the Billboard 200, a career high for the 31-year-old musician. Reviews of “Brat” have been almost uniformly positive, including raves from the likes of Pitchfork, Rolling Stone and the Guardian.

Lorde, about whom Charli is broadly thought to have written the song “Girl, So Confusing,” offered her take on Instagram, writing that “there is NO ONE like this b—”; the New Zealander then jumped on a remix of “Girl, So Confusing” that immediately racked up more than 5 million plays on Spotify after it dropped on Friday. And this fall, Charli will play arenas on a co-headlining tour with Troye Sivan.

For all her swagger at the Shrine, Charli on “Brat” anticipates the isolating experience of stardom; in the song “Rewind,” she’s already longing for the days “when I didn’t overanalyze my face shape” and when she “used to never think about Billboard.”

In fact, she’s not alone: Charli’s sudden ascent is just one of several we’re seeing this summer, including Sabrina Carpenter and Chappell Roan, both of whom are putting up huge numbers after years of work in the trenches of pop music.

This week, Carpenter’s song “Please Please Please” — a slinky yacht-rock jam about a famous woman’s anxieties regarding a public relationship — topped the Hot 100 in just its second week on the chart, followed closely at No. 4 by her frothy neo-disco smash “Espresso”; a few days before, San Francisco’s Outside Lands festival announced that it had tapped Carpenter, 25, as a last-minute headliner to replace Tyler, the Creator after he dropped out for unspecified reasons.

Roan, meanwhile, just entered the top 10 of Billboard’s album chart for the first time with her grandly theatrical 2023 LP, “The Rise and Fall of a Midwest Princess,” powered in large part by the 26-year-old’s much-discussed appearances at Coachella and New York’s Governors Ball festival. Asked by Jimmy Fallon on “The Tonight Show” the other day what it felt like to finally break through, Roan smiled and said, “It feels like I was right all along.”

So why now for these women — and in a year crowded with activity, no less, by veteran A-listers like Taylor Swift, Beyoncé and Billie Eilish? One top pop songwriter, granted anonymity in order to speak candidly, points out that part of what’s happening is merely a course correction for a music industry that’s been starved for new superstars.

“The last one was Olivia Rodrigo, and that was almost four years ago — that’s not normal,” this person says. “There used to be at least one massive breakout every year, if not two.”

COVID-19 pandemic shutdowns deprived record labels access “to the traditional levers they used to be able to pull” to elevate young acts, the songwriter adds; TikTok filled the vacuum with short-lived hits by “random people in their bedroom — which is beautiful, but then you realize they’ve never played a show before and there’s nothing to fall in love with. It’s just a song, and you have no clue who’s singing it.”

Yet something connects Carpenter, Roan and Charli XCX in particular that’s clearly resonating with listeners. According to Michelle Jubelirer, the former Capitol Music Group chief executive who helped orchestrate the rise of Ice Spice, “They’re all incredibly strong, independent women who are a little brash and who build worlds and remain authentically themselves.” Jubelirer laughs. “It’s like, ‘We’re done with the bulls—,’” she says. “‘Accept us for who we are, or f— you.’”

That brashness doesn’t just manifest in the winking aggression of a song like Charli’s “360,” in which she promises to “shock you like defibrillators,” or “Please Please Please,” which has Carpenter warning her actor boyfriend not to embarrass her. It’s also in the forthright depiction of queer sex in Roan’s “Casual” and in the naked vulnerability of Charli’s “I Think About It All the Time,” a staticky ballad about how motherhood fits (or maybe doesn’t) into the life of an artist.

“I was walking around in Stockholm / Seriously thinking ’bout my future for the first time,” she sings, going on to recount a visit to friends with a new baby. “She’s a radiant mother and he’s a beautiful father / And now they both know these things that I don’t.”

Sturdily crafted yet rough around the edges, “I Think About It All the Time” reflects the frankly confessional nature of social media, which may be a reason Charli’s music is stirring up more passion than Dua Lipa’s comparatively streamlined “Radical Optimism,” to name one recent album by a far more famous pop singer that’s failed to connect with a mass audience this year.

Ditto, perhaps, for relatively underperforming LPs by Ariana Grande and Kacey Musgraves, both of which presented portraits of women who’d soul-searched their way to a state of emotional equilibrium — as opposed to people (à la Charli, Sabrina and Chappell) owning their unresolved desires and anxieties.

Of course, however happily messy they might appear, each of these ascendant pop stars has honed the ability to express that message through years of practice. Roan signed her first major-label deal almost a decade ago and moved to L.A. from her native Missouri in 2018; Carpenter, who has an album due in August, made her name on a Disney Channel series and released her debut full-length in 2015. As one seasoned insider puts it in regards to former kiddie-TV figures: “Fans grew up with them, so when they break, they’re more than a song because they’re already a part of your life. And the Disney girls are well trained: They can deliver when they need to.”

Indeed, as Jubilerer notes, Roan and Carpenter have consistently gone viral with performance clips that demonstrate their old-school stage talent — talent each of them got to expose to huge audiences on the road this year, Roan as an opening act for Rodrigo (with whom she shares a producer in Dan Nigro) and Carpenter as one of Swift’s openers on the record-breaking Eras tour.

Yet the stage is also where an experienced pro can come face to face with her disorienting new reality. Performing this month in North Carolina, Roan tearfully interrupted her set to tell her audience that she felt “a little off” because “my career is just kind of going really fast and it’s really hard to keep up.” She said she didn’t want to offer up “a lesser show” because of her feelings and added, “This is all I’ve ever wanted — it’s just heavy sometimes.”

The crowd promptly roared.