Kate Middleton surprises with piano duet alongside daughter, Princess Charlotte, for Christmas carol service

Kate Middleton played piano with her daughter, Princess Charlotte, in a sweet mother-daughter duet.

The surprise moment aired on her Christmas Eve "Together at Christmas" carol service as the opening segment.

In the clip, the Princess of Wales sat beside her daughter for a rendition of "Holm Sound" by Erland Cooper.

She shared the moment on the @PrinceandPrincessofWales social media page Wednesday.

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