Nichols and May. John Belushi. Bill Murray. Chris Farley. Tina Fey. Mike Myers. Stephen Colbert. For nearly a half century, Del Close cocreator of the Harold, director for the Second City, San Francisco s the Committee, and the ImprovOlympic, and house metaphysician for" Saturday Night Live "influenced improvisational theater s greatest comedic talents. His students went on to found the Groundlings in Los Angeles, the Upright Citizens Brigade in both...