As she tells it, Jenny Lewis was born in Las Vegas after her mother went into labor while performing at the Sands. Like much of old Vegas, The Sands is no longer standing, but Lewis, who performed at the Anthem on Thursday, is doing her best to keep that spirit alive.

In floor-length sequins and fuzzy cuffs, Lewis looked like a vestige of a long-gone era. As she strutted, posed and played, she oozed effortless, classic cool, with a voice that is aging like the bourbon you save for special occasions.

Lewis made every moment feel momentous as she glided through favorites from her discography, from the country-gospel of her album “Rabbit Fur Coat” to Fleetwood Mac-esque rockers like “She’s Not Me” and the deliciously titled “Red Bull & Hennessy.” Her besuited backing band provided the muscle for her rollicking rockers, and a two-woman string section added grace.

Lewis did the rest, with a showman’s zeal (once upon a time, she was a child actress). She bantered with the crowd, joking about how difficult it was to hop onto a drum riser in that long dress. She explored the subtle recesses of “Happy,” a gentle song that Lewis and her band turned into something befitting the “Twin Peaks” Roadhouse. And before launching into “Born Secular,” she sounded like a big-tent preacher as she told the audience, “It’s okay to be imperfect, it’s okay to have an off day.”

Her command of the crowd never wavered. At one moment, most everyone was sitting; a moment later, halfway through “See Fernando,” almost everyone was on their feet and in a frenzy. Near the end of the song, seemingly a bit verklempt, she bailed on a note and apologized for being “unprofessional.” “With the lights up,” she explained, “I could see you and feel you.” Her fans didn’t care about “professionalism” — they could see and feel her, too.

Perhaps that’s because the audience has been in communion with Lewis for years, back to her days fronting Rilo Kiley. She closed her set with a stripped-down version of the band’s song, “With Arms Outstretched.” Just her voice, a reverb-heavy guitar, and a slow-clapping audience that glowed with smartphone lights and sang along.

Lewis’s songs are indebted to the past, but her lyrics are decidedly modern, whether she’s mixing references with a wink (“click my ruby slippers like Don Quixote”), telling tales (“Took a little trip up north / In a borrowed convertible red Porsche / With a narcoleptic poet from Duluth”), or name-dropping Paxil, the antidepressant, and Candy Crush, the video game.

But for all her precise images and personal touches, Lewis tends to land on universal truths. On “Head Underwater,” she found clarity after a breakup, singing, “There’s a little bit of magic, everybody has it / There’s a little bit of sand left in the hourglass.” As she told the crowd, “This is a true story.”

Is the story of her mom going into labor onstage true? It might as well be. One way or another, Lewis was born to be there.