Conan O’Brien is sixty-two, and he has done, more or less, everything in modern American comedy. President of the Harvard Lampoon. Writer for “Saturday Night Live” and then “The Simpsons.” “Late Night,” starting in 1993. The whole controversy with Jay Leno and the “Tonight Show,” in late 2009. “Conan,” on TBS. A long career in standup. Podcasting. Back in the day, he was a drummer in the Bad Clams. Not a good band, but O’Brien did become a pretty decent guitar player, as you can hear in his performance, with Jack White, of the Eddie Cochran classic “Twenty Flight Rock.”