Believe the hype: Billie Eilish proves she's a once-in-a-generation talent at NYC concert

NEW YORK — You're definitely not the only one with questions about Billie Eilish.

"Is Billie a boy or a girl?" a middle-aged woman asked a group of teenage girls waiting outside Radio City Music Hall, where the 17-year-old superstar was playing a sold-out show Wednesday. Other passersby stumbled over her unusual surname ("Do you say Eyelash?") and attempted to classify her sound ("I think she makes weird indie music?"), before going about their days with a shrug.

You could be forgiven for not being totally up to speed on Eilish – after all, few artists have enjoyed a quicker ascent. In April, she bowed at No. 1 on the Billboard 200 album chart with her debut "When We All Fall Asleep, Where Do We Go?" less than two years after releasing her "Don't Smile at Me" EP. A case study for commercial success in the streaming era, she's steadily amassed more than 1 billion Spotify streams in the U.S. with a string of one-off singles and cultivated an Instagram following of 26 million, thanks in part to her eye-popping fashion and candid videos.

Judging by the throngs of youngsters who swarmed on Radio City with their parents Wednesday night, Eilish's fans think of her as a big sister and style icon. Girls as seemingly young as 6 years old, and as old as 22, arrived at the venue decked out in oversize hoodies, baggy shorts, neon-green beanies and bucket hats (all trademarks of Eilish's wardrobe, along with her blue hair, which some fans also sported).

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Their screams were deafening when Eilish swaggered onto the stage to perform her throbbing No. 2 hit "Bad Guy" at the top of the show, jumping in step with their fearless leader as they shouted all the lyrics back to her. You wouldn't know that "Bad Guy" is Eilish's highest-charting single judging by her concert, where every song played like a kinetic stadium anthem, down to doleful deeper cuts "Ilomilo" and "When I Was Older."

That's thanks in large part to Eilish's infectious charisma and tangible chemistry with her young audience. Surrounded by projections of killer sharks and dead-eyed monsters, she brazenly bounced across the light-up stage with a smile, tugging at her shirt and reaching her microphone into the crowd so fans could sing along. But she also slowed things down on occasion, showing off her husky, lilting voice as she cradled her mic stand and channeled Amy Winehouse with ballads "Xanny" and "Wish You Were Gay," a cheeky highlight.

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Eilish kept the conversation to a minimum as she ran through her 20-song set, save for a sweet introduction to her brother, producer Finneas O'Connell, who joined her for sentimental favorite "I Love You," which they performed atop a floating bed. She later capped the show with a subtly radical message to her fans, encouraging them to live in the moment and not shy away from their emotions, whatever those might be.

"If right now you feel amazing or right now you feel absolutely horrible, I want you to live in that feeling, whether it's a good feeling or a bad feeling," Eilish said to cheers. "If this is the best night of your life, (expletive)! If you hated this and this was the worst night of your life, live in that, too, because that's you, bro! Do you."

It's encouraging to see an artist as unapologetically sensitive and strange as Eilish at the forefront of today's pop music. With her as their guide, we're happy to report that the kids will be all right.

This article originally appeared on USA TODAY: Believe the hype: Billie Eilish proves she's a once-in-a-generation talent at NYC concert