Every Friday night on the Late Show with David Letterman Dave takes time out to read and answer actual letters from actual viewers. Along with the Top Ten Lists, Viewer Mail has been a David Letterman staple since the debut of Late Night with David Letterman on NBC. These days it is officially called the CBS Mailbag (the words "Viewer Mail" were NBC intellectual property...same reason why it's Calvert DeForest and not Larry 'Bud' Melman anymore) but its still the same old wonderful bit.
On the Late Show the segment is opened with the following song performanced by Paul Shaffer and the CBS Orchestra:
Letters
We get letters
We get sacks and sacks of letters
LETTERS!!
Recently, Dave read a letter which suggested the final line of the song be SACKS!!!! because SACKS is an inherently funny word. Paul and the band's response was to sing the song with the following as the last line: "{insert letter writer's name here} should mind his own fucking business!"
In the late 80s there was a Viewer Mail song on the Late Night show as well:
Viewer Mail!
Viewer Mail!
Friday is the night we read viewer mail
First we read them, then we answer them
That's the little bit we call viewer mail.
I recall the night that Paul retired the original Viewer Mail song he had Henry Mancini come out and accompany him. Mancini might have actually written the Viewer Mail song, but I'm not certain. Hey, it was ten years ago...
Personally I liked the segment a lot more when people wrote actual handwritten letters. Often the stationary or penmanship was part of the joke. Nowadays most letters are printouts of emails. Blah.