The Duchess of Cambridge beat out a festive rhythm when she joined a group of youngsters for a drumming workshop at a children's mental health centre.
Kate was left with sore hands after her 15-minute session with pupils, and their parents, from a school run by the Anna Freud Centre, a leading charity in research, teaching and the provision of care for children and young people with mental health issues.
She also revealed that she is a fan of Chelsea Football Club and was given a high five by one little boy when the pair discovered they supported the same team.
The Duchess's red Alexander McQueen outfit meant she was unable to hold the instrument between her legs like everyone else so instead placed it to one side.
But she still pounded the West African djembe drum with the palms of her hands and smiled and laughed as she followed the deafening rhythms, similar to the beat from the Queen song We Will Rock You.
Kate was an enthusiastic drummer despite sitting between two expert youngsters, Kai Bromley and Capone Duggan, both 12, who played solos.
The Duchess had joined the school's Christmas celebrations at the centre in King's Cross, central London, and Capone, from Hackney, east London, described how he helped their famous guest.
He said: "We were speaking about how to hold the drum. I was showing her how to do it but it wasn't easy for her to hold it properly because she was in a dress.
"Everybody was having fun, she really enjoyed it. She was making the right sound. My hands were sore and she asked me how they were and she said her hands were also sore."
The session had been taken by Jude Winwood, founder of the drumming workshop BeatFeet, who said: "The drumming gives the children a voice and they can express themselves when words aren't enough.
"I thought the Duchess was fantastic, she has such good rhythm, she dug in deep and coped really well."
When Kate first arrived she joined the children and their parents at tables where they were making paper copies of their hands.
The hand designs formed part of a Christmas tree collage celebrating the children's achievements this term with positive messages written on the fingers.
At one table the Duchess was given a high-five by Rjay Bryan, aged eight, when the pair found out they supported the same football team.
The schoolboy said after meeting Kate: "I gave her a high-five because she supports Chelsea and I support Chelsea."
He joked about her husband William supporting Aston Villa - the Premier League's bottom team: "William supports Aston Villa - oh come on."
His mother Ellen Bryan, 45, from Harlesden, north-west London, said her son had been excluded from school aged just six because of behavioural problems, but after spending a year at the school run by the centre was returning to mainstream education in the new year.
Kate was making her second trip to the Anna Freud Centre after visiting the institution in September and many of the children she had met before.
The centre is named after the pioneer of child psychoanalysis - and daughter of the famous psychoanalyst Sigmund Freud - who was instrumental in its creation.
She set up the Hampstead War Nurseries in 1941 in response to the social and emotional upheaval faced by children in wartime, and over the decades it developed into a centre of teaching and research and a major service provider.
The Duchess gave a short address before leaving, telling the staff, children and parents: "Thank you everyone, it's been so fantastic to see you all again, doing amazing things, so keep it up and have a really happy Christmas."
Peter Fonagy, chief executive of the Anna Freud Centre, told Kate: "Your Royal Highness, what you do for children's mental health is actually unique.
"I do not know anyone else who speaks up for children and their emotional and behavioural problems.
"It is of enormous importance to us who work in the field, it is of enormous importance to the people who try and deal with these problems day in and day out."
Before leaving Kate was given a hug by Rjay who also presented her with a necklace with a little drum at the end of it, in memory of her music lesson.
Copyright (c) Press Association Ltd. 2015, All Rights Reserved. Picture (c) Chris Jackson PA / Wire.