Like other talk shows, the show features at least two or three guests each night, usually including a comedian or musical guest.
When Letterman moved to CBS and began the Late Show, many of the shows long running jokes and gags made the move along with him, much to the dismay of NBC which claimed to own many of them. Letterman got around any potential legal problems by simply renaming a few of them. For example, "Viewer Mail" became the "CBS Mailbag," and Larry "Bud" Melman began to use his real name, Calvert DeForest. Perhaps as a response, Letterman's talk-show idol Johnny Carson, allowed Letterman to use one of his old gags, "Stump The Band," which has become a regular feature on the Late Show.
On September 17, 2001, The Late Show with David Letterman returned to the television airways six days after the September 11, 2001 Terrorist Attack in the United States. In his opening monologue a very emotional David Letterman said, "We're told that they were zealots fueled by religious fervor... religious fervor... and if you live to be a thousand years old will that make any sense to you? Will that make any goddamn sense?"
Letterman frequently uses crew members in his comedy bits, so viewers get to know stage hands and writers almost as well as they do the host. Common contributors include: bandleader Paul Shaffer, Calvert DeForest, announcer Alan Kalter, stage manager Biff Henderson, scenic designer Kathleen Ankers, stage hand Pat Farmer, stage hand Kenny Sheehan, handyman George Clarke, local gift store owners Sirajul Islam and Mujibur Rahman, Rupert Jee (owner of the Hello Deli, which is next door to the Ed Sullivan theater), producer Maria Pope, assistant Stephanie Burkett, Kiva Kahl the "Grinder Girl," and models Andrea Sande and Nadine Hennelly.
Classic gags include