The Queen has been seen with several other members of the Royal Family for the first time since the start of the coronavirus pandemic.
Her Majesty, 94, was joined by the Prince of Wales and Duchess of Cornwall, Prince William and Kate, the Earl and Countess of Wessex, and the Princess Royal, who all stood socially distant by the steps of Windsor Castle.
A Salvation Army band played festive tunes as three generations of royals enjoyed a Christmas carol performance - with the monarch singing along quietly.
When the performance ended, the Queen, who wore a red hat and coat, and a ruby and diamond spray brooch, chatted to her family.
Commissioners Anthony and Gillian Cotterill, from the Salvation Army, also spoke to the monarch who told them "nobody's allowed to sing anymore".
Choirs can perform in the open air and Princess Anne told her mother: "Oh, we can sing outside."
As the Queen turned to walk up the steps back inside her castle home, Prince William said: "Bye gran."
The royals then chatted to local volunteers and charity workers in a marquee where the guests were served mulled wine and a non-alcoholic punch and mince pies.
Mr Cotterill said: "The Queen was saying she was just so happy we were able to play some carols because she thinks this will be the only time she'll be able to hear carols, and she was disappointed we didn't sing.
"Sometimes we're playing musicians and other times we're a choir, at an event like this it's better to have the band as you can hear it for miles."
Mrs Cotterill added: "I did see the Queen mouthing some of the words - so that was nice."
Prince William and Kate went to the castle after earlier completing their royal train tour of the country where they thanked healthcare staff for their work during the pandemic.
