Patrick Woodroffe is the world's foremost live show lighting designer. He's the man the Rolling Stones, Bob Dylan, Stevie Wonder and many others ask for by name. He's been behind some of the most ambitious and technically demanding stage presentations, from vast crowds on Copacabana Beach to a world TV audience for the opening ceremony of the 2012 Olympics. He talked to Mark Ellen and David Hepworth about his work in front of an audience at the Islington.