The 39-year-old Duchess of Cambridge hosted the programme, appearing alongside her husband Prince William for the special royal carol service at Westminster Abbey.
Several famous faces were spotted in the audience or on stage, with both Leona Lewis and Ellie Goulding performing, reports OK!.
But in an unexpected moment for the Duchess mum-of-three, she also took to the stage herself and elegantly played the grand piano.
She was joined by Tom Walker, who sang the poignant “For Those Who Can’t Be Here” in tribute to all those who lost their lives in the Covid pandemic over the last year.
With millions of viewers watching in awe at home, former GMB host Piers, 56, took to his social media to weigh in.
“A proper Duchess,” he wrote simply, sharing a beautiful still of Kate smiling at the piano.
Thrilled with the incredible opportunity, Tom tweeted his thanks to the Duchess after the stunning performance finished.
“WHAT A NIGHT I can’t thank @KensingtonRoyal enough for being a part of this performance,” he gushed.
“This is dedicated to those who can’t be here this Christmas including my grandad.
“He definitely would have been bragging about this to his mates down the pub.”
The official Twitter account for the Duke and Duchess also posted a clip of the pair’s wonderful performance as Kate kept her poise throughout.
“A very special performance of ‘For Those Who Can’t Be Here’ with @IamTomWalker for #TogetherAtChristmas,” it read.
Kate has played the piano since childhood and is very experienced with the instrument.
Despite that, the Duchess is said to have met up with the Scottish musician, who also played his guitar during the performance, in secret so they could rehearse together before filming.
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