A fan of Dolly Parton gets a masterclass from the queen of country.
Nicola Roberts duets with a fan, and Chris Boardman races a cycling-mad fundraiser.
Beverley Knight duets with one of her biggest fans.
Pop sensation Sophie Ellis-Bextor duets with a brave young woman.
Mel C takes to the stage with one of the Spice Girls' biggest fans.
Legendary soprano Dame Kiri Te Kanawa duets with an aspiring opera singer.
John Barrowman chooses some of his most memorable moments from the series.
A woman sings a duet with Dusty Springfield, and a golf fan meets Colin Montgomerie.