Tine Thing Helseth at Norwegian Christmas tree on Trafalgar Square

1. In the Bleak Midwinter

Tine plays In the Bleak Midwinter on stage on Trafalgar Square to celebrate the lighting of the tree.

2. Tine Thing tweets a picture ahead of the lighting

Before the Norwegian tree was lit, Tine posted a picture of herself on Twitter ahead of her sound check.

3. Tine Thing Helseth meets The Lord Mayor of Westminster

Trumpeter Tine and the Lord Mayor of Westminster, councillor Angela Harvey shake hands on stage in front of the tree.

4. Tine Thing Helseth

Tine also performed at the Regent Street Christmas lights, with singer Noah Stewart.

Tine Thing Helseth at the Norwegian Christmas

5. The Norwegian Christmas tree

The view from afar, as the beautiful lights bring London's Trafalgar Square to life.

6. Tine Thing Helseth at the Norwegian Christmas tree

Tine receives a well-deserved round of applause after her performance of In the Bleak Midwinter.

7. Tine Thing Helseth, the choir of St Martin in the Fields

Members of the choir of St Martin in the Fields sing alongside Tine Thing Helseth, performing The First Nowell and The Holly and the Ivy.

8. The Norwegian Christmas tree

Measuring an impressive 52 metres, the tree towers over the performers on London's Trafalgar Square.

9. The Norwegian Christmas tree

Lord Mayor of Westminster, councillor Angela Harvey said: “I would like to thank the people of Oslo for this wonderful tree, the gift of which is a tradition that goes back many years, and has come to represent not only the start of Christmas, but also a long-standing friendship between Norway and the United Kingdom.”