Gigi Hadid has a secret singing past that you didn't know about -- find out who she sang backup for!

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Did you know that Gigi Hadid could sing? We didn't either ... until now.

First, a little background:

The 21-year-old model has been dominating the fashion world for the past couple of years, with her fame skyrocketing her to become the most in-demand model in the world. Along with her younger sister, Bella, and friends like Kendall Jenner and Joan Smalls, Hadid has led a new crop of beautiful young women down the biggest runways in the world.

SEE ALSO: Bella Hadid posts the most adorable throwback photo with big sis Gigi

We first became familiar with Gigi and Bella as background players on Bravo's "Real Housewives of Beverly Hills," as they appeared in numerous scenes with their mother, Yolanda Hadid, herself a former model. During her time on the show, Hadid went by Yolanda Foster, because she was married to Grammy-winning musician, David Foster.

Fast forward to this week when we were scrolling through Twitter and happened upon something very interesting and seemingly unknown about the origins of Gigi's career.

When we first saw this tweet by Music News & Facts, we weren't sure we had read it correctly. It claimed that "Gigi Hadid did the background vocals of multiple songs on Josh Groban's album 'Noël,' which sold over 7M copies WW."

Wait, what?! We, like every other person in this world, follow Gigi's every move through her social media accounts and her time on "Real Housewives," and we had never seen her sing one note of music. Ever.

So we did some digging and, turns out, Music News & Facts was on the money with their tweet.

Back in 2007, Gigi's aforementioned step dad, David Foster, produced the best-selling album of the year which was, you guessed it, Josh Groban's iconic Christmas album, Noël. The album went on to sell over 7 million copies worldwide.

Listen to Josh Groban's iconic Christmas album, Noël, here.

Gigi, then 11 years old, is credited on not one but two songs on Groban's album: "Little Drummer Boy" and "I'll Be Home For Christmas."

On "Little Drummer Boy," you can hear the singing voice of a young girl in the background of the chorus repeating the lines as first sung by Groban. We're guessing that's little Gigi!

On "I'll Be Home For Christmas," her appearance is more blatant: "Hi Daddy! Mommy, Bella and I are wrapping presents to put under the tree, and we saved one especially for you," you can hear her saying over one of the song's interludes. "We miss you a lot, and we hope that you come home soon."

So, we knew that Gigi had ties to the music world through her step dad, but we didn't know until this week that she herself dabbled in singing, most likely at the suggestion of Foster himself.

Further, it looks as though Gigi and Groban interacted a couple of years ago on Twitter, alluding to their little-known collaboration.

There you have it! Gigi Hadid has a secret singing past that you never knew about until now. You're welcome!

See photos of Gigi Hadid through the years:

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US model Gigi Hadid presents a creation by Giambattista Valli during the 2016 Spring/Summer ready-to-wear collection fashion show, on October 5, 2015 in Paris. AFP PHOTO / MIGUEL MEDINA (Photo credit should read MIGUEL MEDINA/AFP/Getty Images)
NEW YORK, NY - OCTOBER 08: Gigi Hadid attends the Global Lyme Alliance 'Uniting for a Lyme-Free World' Inaugural Gala at Cipriani 42nd Street on October 8, 2015 in New York City. (Photo by Dimitrios Kambouris/Getty Images for Global Lyme Alliance)
US models Kendall Jenner (L) and Gigi Hadid attend the French L1 football match Paris Saint-Germain (PSG) vs Olympique de Marseille (OM) on October 4, 2015 at the Parc des Princes stadium in Paris. AFP PHOTO / THOMAS SAMSON (Photo credit should read KENZO TRIBOUILLARD/AFP/Getty Images)
PARIS, FRANCE - OCTOBER 01: Gigi Hadid walks the runway during the Balmain show as part of the Paris Fashion Week Womenswear Spring/Summer 2016 on October 1, 2015 in Paris, France. (Photo by Pascal Le Segretain/Getty Images)
NEW YORK, NY - SEPTEMBER 16: Model Gigi Hadid walks the runway wearing Anna Sui Spring 2016 during New York Fashion Week: The Shows at The Arc, Skylight at Moynihan Station on September 16, 2015 in New York City. (Photo by Frazer Harrison/Getty Images for NYFW: The Shows)
NEW YORK, NY - SEPTEMBER 14: Model Gigi Hadid walks the runway wearing Tommy Hilfiger Women's Spring 2016 during New York Fashion Week: The Shows at Pier 36 on September 14, 2015 in New York City. (Photo by Randy Brooke/Getty Images for Tommy Hilfiger)
NEW YORK, NY - SEPTEMBER 14: Model Gigi Hadid walks the runway wearing Jeremy Scott Spring 2016 during New York Fashion Week: The Shows at The Arc, Skylight at Moynihan Station on September 14, 2015 in New York City. (Photo by Frazer Harrison/Getty Images for NYFW: The Shows)
NEW YORK, NY - SEPTEMBER 08: Model Gigi Hadid and Singer Joe Jonas attend the Women's Singles Quarterfinals match between Serena Williams of the United States and Venus Williams of the United States on Day Nine of the 2015 US Open at the USTA Billie Jean King National Tennis Center on September 8, 2015 in the Flushing neighborhood of the Queens borough of New York City. (Photo by Matthew Stockman/Getty Images)
LOS ANGELES, CA - AUGUST 30: Model Gigi Hadid attends the 2015 MTV Video Music Awards at Microsoft Theater on August 30, 2015 in Los Angeles, California. (Photo by Jason Merritt/Getty Images)
SYDNEY, AUSTRALIA - AUGUST 05: Model Gigi Hadid arrives ahead of the David Jones Spring/Summer 2015 Fashion Launch at David Jones Elizabeth Street Store on August 5, 2015 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images for David Jones)
SYDNEY, AUSTRALIA - AUGUST 04: Gigi Hadid poses at the launch of the Guess Spring 2015 Collection at The Butler in Potts Point on August 4, 2015 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images)
SYDNEY, AUSTRALIA - AUGUST 04: Model Gigi Hadid greets fans at Myer Macquarie Centre on August 4, 2015 in Sydney, Australia. (Photo by Mark Metcalfe/Getty Images)
NEW YORK, NY - JUNE 01: Gigi Hadid poses on the winners walk at the 2015 CFDA Fashion Awards at Alice Tully Hall at Lincoln Center on June 1, 2015 in New York City. (Photo by Larry Busacca/Getty Images)
CAP D'ANTIBES, FRANCE - MAY 21: Model Gigi Hadid attends amfAR's 22nd Cinema Against AIDS Gala, Presented By Bold Films And Harry Winston at Hotel du Cap-Eden-Roc on May 21, 2015 in Cap d'Antibes, France. (Photo by Tristan Fewings/Getty Images)
NEW YORK, NY - MAY 14: Models Gigi Hadid and Jourdan Dunn attend Maybelline New York's 100 Year Anniversary at IAC Building on May 14, 2015 in New York City. (Photo by Mireya Acierto/Getty Images)
NEW YORK, NY - MAY 04: Gigi Hadid attends the 'China: Through The Looking Glass' Costume Institute Benefit Gala at the Metropolitan Museum of Art on May 4, 2015 in New York City. (Photo by Larry Busacca/Getty Images)
MIAMI BEACH, FL - MARCH 14: Victoria's Secret Pink model Gigi Hadid attends the Ultimate Spring Break Bash hosted by Victoria's Secret PINK Nation at Surfcomber Miami, South Beach on March 14, 2015 in Miami Beach, Florida. (Photo by John Parra/Getty Images for Victoria's Secret)
MILAN, ITALY - FEBRUARY 26: Gigi Hadid walks the runway at the Moschino show during the Milan Fashion Week Autumn/Winter 2015 on February 26, 2015 in Milan, Italy. (Photo by Fulvio De Filippi/Getty Images)
MILAN, ITALY - FEBRUARY 28: Gigi Hadid walks the runway at the Emilio Pucci show during the Milan Fashion Week Autumn/Winter 2015 on February 28, 2015 in Milan, Italy. (Photo by Andreas Rentz/Getty Images)
BEVERLY HILLS, CA - FEBRUARY 22: Model Gigi Hadid attends the 2015 Vanity Fair Oscar Party hosted by Graydon Carter at Wallis Annenberg Center for the Performing Arts on February 22, 2015 in Beverly Hills, California. (Photo by Pascal Le Segretain/Getty Images)
NEW YORK, NY - FEBRUARY 18: Model Gigi Hadid attends Mercedes-Benz Fashion Week Fall 2015 at Lincoln Center for the Performing Arts on February 18, 2015 in New York City. (Photo by Andrew H. Walker/Getty Images for Mercedes-Benz Fashion Week)
MILAN, ITALY - SEPTEMBER 25: (BRAZIL OUT, NEW YORK TIMES OUT, UK VOGUE OUT) Gigi Hadid walks the runway during the Versace Ready to Wear show as a part of Milan Fashion Week Spring/Summer 2016 on September 25, 2015 in Milan, Italy. (Photo by Victor VIRGILE/Gamma-Rapho via Getty Images).
NEW YORK, NY - JANUARY 05: Gigi Hadid is seen in the Lower East Side on January 5, 2016 in New York City. (Photo by Alo Ceballos/GC Images)
NEW YORK, NY - DECEMBER 08: Gigi Hadid seen on the streets of Manhattan on December 8, 2015 in New York City. (Photo by James Devaney/GC Images)
Model Gigi Hadid arrives at the 2015 American Music Awards at Microsoft Theater on November 22, 2015 in Los Angeles, California.
Gigi Hadid appears backstage in hair and makeup at the 2015 Victoria Secret Fashion Show at the Lexington Armory on Tuesday, Nov. 10, 2015, in New York. The Victoriaâs Secret Fashion Show will air on CBS on Tuesday, December 8th at 10pm EST. (Photo by Charles Sykes/Invision/AP)
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