On Sunday, April 24th, David Gilmour performed for Teenage Cancer Trust at the Royal Albert Hall. While his performance happened with a mission in mind, Gilmour had a surprise up his sleeve: A tribute to rock and pop legend Prince, who died last week. Gilmour performed "Comfortably Numb" as planned, but then went on to include his version of "Purple Rain." Between the swelling guitars of Gilmour's band and the appropriately-lit stage, this performance is one you're going to want to watch.