He had an early morning show for a while which was deservedly a ratings disaster and then moved on to his Late Night show which made him a star. His humor on that show was often wonderfully eccentric and quite funny.
He lost that edge when he moved to CBS and became little more than a dyspeptic curmudgeon, perhaps as a result of jealousy over the funnier and far more likable Leno.
It is interesting to contemplate how Letterman and Carson were two complex, driven, privately unhappy, but very popular comedians. Someone once noted that at the basis of much humor is anger, and these two seem to capture that notion in toto.
and Carson wanted letterman to take his place and they were fairly close after that Carson even did a cameo on Letterman’s show
Wow! I'm not sure if I'm more surprised that Letterman was actually funny once, or that the Starland Vocal Band had a show. Well, I guess a one-trick pony for a one-hit wonder has a certain karma to it.