Catherine, Princess of Wales, 43, and her daughter Princess Charlotte, 10, have played the piano together as part of the introduction to the Princess of Wales's 'Together at Christmas' Carol Service.
The Princess of Wales's Christmas Carol Services at Westminster Abbey have started to become a British Christmas tradition over the last few years.
In the piece, Their Royal Highnesses play Holm Sound by Erland Cooper, a Scottish composer, producer and multi-instrumentalist, originally from Orkney, whose work is inspired by nature and connection, themes which are of deep importance to the Princess of Wales.
Her Royal Highness Princess Charlotte, 10, is third in line to the British Throne, after her father Prince William, 43, and older brother Prince George, 12.