The Princess of Wales hosted her fifth “Together at Christmas” carol service at Westminster Abbey in London on Dec. 5

The Princess of Wales and Princess Charlotte play Erland Cooper’s Holm Sound at Windsor Castle, as featured in the Together at Christmas Carol Service.Credit : Andrew Parsons/Kensington Palace

Kate Middleton’s “Together at Christmas” carol service featured a surprise duet from her and her 10-year-old daughter, Princess Charlotte.

The Princess of Wales, 43, hosted her fifth annual Christmas carol service at Westminster Abbey in London on Dec. 5.

During the broadcast of the concert, which aired on the U.K.’s ITV on Thursday, Dec. 24, at 2:25 p.m. ET, royal fans were treated to a performance by Kate and Charlotte on the piano. The mother and daughter duo played “Holm Sound” by Erland Cooper.

“At its heart, Christmas speaks of love taking full bloom in the simplest, most human ways,” Princess Kate said in a clip posted on Instagram. “Not in sentimental or grand gestures, but gentle ones, a moment of listening, a word of comfort, a friendly conversation, a helping hand. Presence. These simple acts of care might seem small, but they contribute to the beautiful tapestry of life to which we all belong.”

The Prince and Princess of Wales’ social media accounts had teased the duet between the mother and daughter earlier in the day.

In a video posted on Instagram hours before the service aired, the camera could be seen panning across a piano to show Kate’s hand — identified by the royal’s stunning sapphire engagement ring — resting on the keys and soon being joined by another hand in frame that appeared to be her daughter’s.

The Princess of Wales and Princess Charlotte play Erland Cooper’s Holm Sound at Windsor Castle, as featured in the Together at Christmas Carol Service.Andrew Parsons/Kensington Palace

The shot then faded out and the words “Kensington Palace” flashed up on the screen alongside vines of ivy.

“A special duet… 💕,” the clip was captioned. “Watch Royal Carols: Together at Christmas tonight at 7.25pm on @itv and @itvxofficial,” was added in the comments section.

The annual service was also attended by Prince William, Prince George, 12, and Prince Louis, 7, with the family all pictured outside Westminster Abbey, which is where William and Kate wed in 2011.

Other members of the royal family among the 1600-strong congregation included Sophie, the Duchess of Edinburgh and Zara Tindall and her husband, Mike Tindall. Princess Kate was also supported by her parents, Carole and Michael Middleton, and her brother, James Middleton, who was joined by his wife, Alizée Thevenet.

Kate wrapped up warm for the occasion in a long green jacket with fur trim around the neckline and black boots, while Charlotte wore a navy blue dress with a white Peter Pan collar and matching tights.

In November 2023, Princess Kate revealed her daughter was following in her musical footsteps and pursuing piano while attending the Royal Variety Performance at the Royal Albert Hall in London.

She touched on the topic while speaking to pianist Lang Lang at the annual event, Hello! magazine reported at the time.

“We talked about Charlotte. Her Royal Highness talked about Charlotte’s piano playing, I’m sure she’s good,” the pianist said, per the outlet. “Her Royal Highness said to me that she said to Princess Charlotte ‘Hey, look, if you practice a lot you can be like him.’ ”

The Princess of Wales and Princess Charlotte play Erland Cooper’s Holm Sound at Windsor Castle, as featured in the Together at Christmas Carol Service.Andrew Parsons/Kensington Palace

Kate’s hidden talent for playing the piano was revealed in 2021 during her first “Together at Christmas” carol service.

That December, the royal accompanied Scottish singer-songwriter Tom Walker on the keys in her first public performance for a rendition of his song  “For Those Who Can’t Be Here.”

Princess Kate launched “Together at Christmas” as a thank you to individuals in the U.K. who helped their communities during the COVID-19 pandemic.

The Prince and Princess of Wales with their children at Westminster Abbey.Aaron Chown – Pool/Getty

The theme of this year’s holiday event — “love in all its forms” — was revealed on Nov. 13.

“This year, the Service will bring people together to celebrate love in all its forms — whether it’s love within families, through friendships, across communities or even through powerful moments of connection with strangers. In a world that can often feel fragmented and disconnected, love is the force that reconnects us all – spanning generations, communities, cultures and faiths,” a statement from Kensington Palace said.

“As we approach the Christmas season, we are reminded of the power of togetherness. The evening will highlight the transformative power of investing in one another with compassion, presence and joy,” it added.