The BBC delves into its archive for the best romantic duets performed at the BBC over the last 50 years. Whether it is Robbie and Kylie dancing together on Top of the Pops or Kris Kristofferson and Rita Coolidge singing into each other's eyes on the Whistle Test, there is plenty of chemistry. Highlights include Nina and Frederik's Baby It's Cold Outside, Dolly Parton and Kenny Rogers, Sonny and Cher, Shirley Bassey and Neil Diamond, Peaches and Herb, and a rare performance from Peter Gabriel and Kate Bush.