Olly Murs, Craig David and Little Mix are among the stars who have surprised project workers funded by BBC Children In Need for the chance to duet with them.
Also taking part in the charity appeal's Project Sing were Sheridan Smith and Alfie Boe, who offered up the chance to take part in a celebrity duet.
Project workers Caroline Kennedy (pictured) and Parmi Dheensa thought they were taking part in filming a special music video for BBC Children in Need, but were shocked to learn they would be performing with a star.
Murs performed his hit song Dance With Me Tonight with Kennedy and learned about the work that she does for project Act To Shine, a BBC Children in Need funded project which is part of the M6 Theatre Company, based in Rochdale.
Murs (pictured) said: "It feels so good to get out and about to meet the people that are at the front line of what BBC Children in Need do. They are inspiring and should be celebrated."
David performed single I Know You with Dheensa and learned about the work she does for project TIMEOUT, which is part of charity Include Me TOO, based in Wolverhampton.
David said: "It was amazing to meet one of the project workers funded by BBC Children in Need and to hear about the incredible work she does, it was a great honour."
The surprise duets will be part of BBC Children In Need's appeal night on November 16 on BBC One at 7.30pm.
STACEY DOOLEY TO EXPLORE YOUTH HOMELESSNESS FOR CHILDREN IN NEED
Stacey Dooley will uncover stories from the UK's homeless teenagers in a new film for BBC Children In Need.
The Strictly Come Dancing star will aim to shine a light on the extent of the problem of youth homelessness and show viewers what it is like to live on the streets.
She said: "We were particularly interested in focusing on youth homelessness because I think people have preconceived ideas that young people who are at risk of homelessness are perhaps a higher priority or better taken care of and that they assume it's older people, an older generation that are struggling without a fixed address.
"So we wanted to explore that and see what was really going on."
She added: "I personally learnt that I'd underestimated the problem, it's actually enormous. Over 100,000 young people were homeless, or at risk of homelessness, last year.
"But the experts claim the real figure is probably much higher. I just didn't realise the scale of the issue."
Dooley said she wanted the young people in the film to be "given a voice, given a platform".
The film focuses on peopled aged between 17 and 19 and when she was that age Dooley said her life was "miles away from where these young people are."
She added: "I never worried about where I was going to stay the night; I never worried about having a bath or something to eat.
"I think for me, that's what was most sobering; to see what their worries are compared to my worries at their age. I was worrying about whether I had enough money to go out, or if I had money for a new outfit. That was very sobering. "
Stacey Dooley: The Young and Homeless for BBC Children in Need will be on BBC One on November 13 at 10.45pm.
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