Billie Eilish's Glamorous 2021 Met Gala Look Was Inspired by Her Favorite Barbie Doll

Billie Eilish is the bell of the (Met) ball!

The songstress, 19, made her debut at The Metropolitan Museum of Art's Costume Institute Gala, and she did not disappoint. Eilish switched up her signature grunge-inspired style in a major way, arriving in a peach Oscar de la Renta corset ball gown with off-the-shoulder tulle details and a long train flowing behind her.

She completed the Old Hollywood-inspired look with a blonde lob, sultry black eyeliner and a pinky-brown lipstick. "It just was time," the singer told Keke Palmer on the red carpet of her fashion risk. "It was time for this, and I feel like I've grown so much in the last few years."

Eilish continued, "I've always wanted to do this. I was just scared and didn't feel comfortable in my skin and I feel like I finally did."

As for the inspiration behind her look, the star said holiday Barbie played a huge part! "It was my favorite thing in the world," she said with a smile. "I would ask for them for Christmas every single year. The dresses, genuinely that was my inspiration."

Making her first Met even more of a moment, this year Eilish serves as co-chair alongside fellow Gen Z trendsetters Timothée Chalamet, Naomi Osaka and Amanda Gorman.

When Vogue confirmed in May that Eilish would be the youngest Met Gala co-chair in history, the outlet explained that her "willingness to embrace an aesthetic as innovative as her music has pushed emerging brands into the limelight and challenged old rules about how a pop star should dress."

Be sure to check out all of PEOPLE's Met Gala coverage to get the latest news on fashion's biggest night.

When it comes to her style, Eilish is known to push boundaries with edgy pieces. She's hit the red carpet in a number of bold looks, including: graffiti-print sweats, head-to-toe logo pieces from Burberry, Gucci, Louis Vuitton and more. She doesn't shy away from vibrant colors and eye-catching patterns.

As for her duties, according to British Vogue, past co-chairs (which has included Lady Gaga, Harry Styles, Amal Clooney, Rihanna and Donatella Versace in recent years) have taken the stage during the famed Met Gala dinner. The outlet also revealed that co-chairs help with the guest list, food, decor and the "general feel of the evening."

The theme for the star-studded event (which comes after a canceled 2020 Met Gala and a postponed May date) is In America: A Lexicon of Fashion. Honorary chairs for the evening will be Tom Ford, Adam Mosseri and Vogue editor-in-chief Anna Wintour.

Earlier this year, PEOPLE reported that the annual gala is enforcing a COVID-19 vaccination mandate and mask requirement.

"Currently, all attendees at The Met Gala on September 13 must provide proof of full vaccination and will also be expected to wear masks indoors except when eating or drinking," a spokesperson for The Met confirmed to PEOPLE in August. "We will update these guidelines as needed."