Frequent Zero 7 / David Guetta collaborator, Sia, is the creative force behind Rihanna’s latest smash, “Diamonds”. Here, you can watch her beautifully perform the track on stage to little fanfare, with nothing but a piano backing her. In the second clip, she speaks on the origins of the track, suggesting that it took “22 minutes to write the lyrics and 26 minutes to record the full demo.” Pretty awesome, we hope she was paid handsomely.