Here's a 1977 appearance by Rodney Dangerfield on Johnny Carson's show. Keep your eye on Johnny and you'll see one of the secrets of his success. He was not only willing to play straight man for another comedian, he actually enjoyed it. The whole spot at the desk would have been ruined if Johnny had tried to steer the conversation or insert a joke of his own. A lot of hosts would have thought, "Hey, it's my show, I'm supposed to get some laughs too."