Singer Alicia Keys pays tribute to her friend and "sister" Serena Williams for the BBC iPlayer series Legends, as part of BBC Sport's Change the Game campaign.

WATCH MORE: Legends on BBC iPlayer

BBC Sport has launched #ChangeTheGame this summer to showcase female athletes in a way they never have been before. Through more live women's sport available to watch across the BBC this summer, complemented by our journalism, we are aiming to turn up the volume on women's sport and alter perceptions. Find out more here.