text: Letterman would then walk out on the show stage to perform his stand-up monologue, which occasionally began with a reference to something an audience member said to him during the pre-show question-and-answer session. The jokes were based on pop culture, current events, and politics. He then introduced one or two video jokes such as a running gag or fake commercial/public service announcement. The monologue was followed by Letterman's introduction of Shaffer and the CBS Orchestra. Beginning in 2009, a commercial break replaced Letterman's trademark 'crossing to the desk', which he had done since the early years. Letterman then chatted with the audience and Shaffer, sometimes relating an anecdote from his personal life, sometimes discussing his anticipation of a particular guest; a running gag may have been featured.
  In 2005, after the death of Johnny Carson, it was revealed that Carson had made a habit of sometimes sending jokes to Letterman which Letterman would then incorporate into his monologues. The January 31, 2005, episode of the Late Show, which featured a tribute to Carson, began with a monologue made up entirely of jokes written by Carson since his retirement.
  Letterman read the Top Ten List at this point before turning to guest interviews with a celebrity, politician, or other public figure. On most episodes, the first guest stayed on through the commercial break and continued the interview.
  Following the first guest was a short segment to bridge two commercial breaks sequentially. In earlier episodes, Letterman would return to his running gag during this break, or retry a failed stunt from earlier in the show. Later episodes included a brief comedy announcement from announcer Alan Kalter while showing the audience cheering.