The singer with the Celtic supergroup got into the Christmas spirit ahead of her performance at the Glasgow Christmas Carol Concert tomorrow. Tickets are still on sale for the Glasgow Cathedral event which will also feature Britain's Got Talent winner Jai McDowall.
Karen said: "It was lovely joining with the young Junior Choir singers of the High School of Glasgow who have so much talent.
"I'm really looking forward to the concert which is sure to get us all in the mood for Christmas. And I'm certain the Glasgow community will rally round to help Cancer Research UK raise funds for its life saving work to help beat cancer sooner."
Hosted by broadcaster Sally Magnusson, the audience can also look forward to performances by musicians from McOpera - the orchestra of Scottish Opera - and The Dance School of Scotland at Knightswood.
Also singing will be the Erskine Stewart's Melville School Choir, the ScottishPower Pipe Band and these youngsters from the High School of Glasgow.
The concert in Glasgow Cathedral has raised more than £300,000 since it began in 1999.
One of the concert organisers and former Lady Provost, Sheena Duncan Winter, added: "This year's Glasgow Christmas Carol Concert will be a treat for music lovers of all persuasions given the wide array of talent who have so generously donated their time to entertain us on the night.
"By buying a ticket to the Carol Concert, you are giving a truly special Christmas gift. Cancer Research UK receives no government funding for its ground-breaking research and so please do come along on what will be a splendid and entertaining evening."
To purchase tickets contact Rowan Main on 07918 034 938 or firstname.lastname@example.org