The walkover, or walk-on, for those who don’t speak backstage, is the song that the band plays as a guest comes out from behind the curtain and walks over to the host’s desk. Once upon a time, maybe, it was straightforward, a little musical cue or song associated with the artist. But then came Paul Shaffer’s work on “Letterman,” and the walkover became its own little art form — an obscure musical reference that the audience (and sometimes even the guest) had to decode.FYI, before Shaffer and Letterman in the 1980s, Bobby Rosengarden was doing this sort of thing as Dick Cavett's bandleader in the 1960s and 1970s:
On the Cavett show, he would accompany a seemingly endless of entertainers and banter with Mr. Cavett, and he became known for signaling “walk on” themes for each guest. When a guest who was a sex therapist was introduced, the band played “I Can’t Get Started”; the artist Salvador Dali was greeted with “Hello, Dolly.”"The Dick Cavett Show" never gets enough credit.