Halsey didn’t say too much about herself during the first stop on her first tour as an arena concert headliner Friday night.

Between solid renditions of her post-apocalyptic pop anthems and break-up songs, the screaming crowd at Mohegan Sun Arena got only a few spoken words out of the singer, born Ashley Frangipane on that day 23 years earlier.

The closest she got to personal exposition came in the form of a birthday story: not a lot of people came to her Halloween-themed birthday party as a kid, even though her parents had rented a fog machine, an extravagance for a family that didn't have a lot of money, she told the crowd.

They took a break from screaming to collectively sigh, mourning little Ashley’s small birthday budget and her friends’ callousness.

The story has a happy ending, though. Smoke machines?

“I have a lot of those now,” she quipped. “And it’s OK because this is the biggest birthday party I’ve ever had.”

That was enough backstory to satisfy Halsey's fans. They were there to see her, scream at her, maybe even be sprayed with champagne by her.

Because everything else about her they could read on their phones before the show, during the show, after the show. In the backseat of the car they can read about how endometriosis prevented her from having sex for six months. In study hall they can pull up a Rolling Stone profile where she calls herself a former “stoner kid.” On her Instagram feed, they could see her dog with its tongue out, or her boyfriend, the lanky rapper and record producer known as G-Eazy, also with his tongue out.

“I’m about to figuratively punch u in the emotional face,” she wrote about the tour in the caption on her Instagram post of the dog. “I cried 5 times. I hope you cry even more.”

Just looking at the nearly full arena, it was clear many of the fans saw themselves in Ashley the bipolar stoner kid and Halsey the tattooed, biracial, expletive-dropping pop star. They identified with her as a girl who holds hands with girls, a teenager who feels out of place but can’t explain why, as a goth kid with a disability, or a brown kid surrounded by whiteness.

“She’s different,” one pre-teen said on her way out of the show.

“There’s a story behind her lyrics,” said an adult fan in line for nachos.

That story — Halsey’s mishmash of American identities and modern willingness to share all of them with her fans — is what brought them there.

So they didn’t need to hear the details at the show Friday, the kickoff of a 29-city tour that marks a milestone in a music career that began online while Halsey was couch-surfing in New York.

They already knew what she meant when she said “you guys make me feel like I am so much less alone in the world.” When she shouted, “Yeah, I bet you (expletive) know this song,” they did. And when she gyrated against the dancer who joined her onstage, a “multi-talented artist” who goes by the stage name HeyTeeTee, the crowd caught the wink at sexual fluidity and cheered even louder.

Halsey was comfortable onstage, bouncing through two hours of favorites and new music from her most recent album, "Hopeless Fountain Kingdom," released in June. She played off a wardrobe malfunction quickly and charmingly with an off-color joke.

Fluids featured prominently in the color-saturated CGI images and animated clips projected behind the stage and onto surfaces around the arena. A huge, realistic goldfish swam on a screen behind her in bright turquoise water. The show opened with an image of a shimmering Los Angeles reflected in a puddle, then another song was illustrated with unlabeled plastic bottles chilling in a refrigerator. The screen showed underwater footage of a clear pond or swimming pool.

Halsey and HeyTeeTee later changed into combat boots and mesh hoodies to strut through the center of the arena onto a smaller stage covered with water, which the pair vigorously stomped, splashing everyone in a 10-foot radius.

In Halsey’s world, and in the world of her audience, nobody has to be one thing. Identities can change, pair up, break apart and be interpreted in any way you want. A suburban high-schooler can mark herself as a rebel with the word printed in all-caps on a white crop top, and maybe it can be true. A 24-year-old in a lacy black dress can yell along to lyrics that say she "sold her soul to a three-piece," and maybe that can be true, too. And it can all change tomorrow, without being contradictory.

At the end of Friday's show, certainly past the bedtime of many of the younger members of the audience, Halsey watched a video of friends and family wishing her a happy birthday.

"Happy birthday, Ash," they all said, speaking to the woman the audience knew as Halsey, who sat enraptured on the stage in a boxer's robe of white satin. "Hi Ashley, it's your platonic friend John," said John Mayer, who must be a jarring addition to Halsey's social circle only a few years after she was recording music in strangers' basements. "What a whirlwind ride this has been," said Ashley's dad, seeming genuinely flabbergasted.

Halsey handled this melding of her past and present in front of thousands of people with grace, and kept it together when G-Eazy appeared onstage to lead the audience in a very loud version of "Happy Birthday."

She took a running leap, kissed her boyfriend on the lips, then launched into encore performances of two songs from her 2015 debut studio album, "Badlands."

"This song is a reminder that you do not belong to anybody but yourself," she cried. And the kids screamed some more.

m.shanahan@theday.com