Like some mythological creature – half man, half desk

Walking down Broadway last Sunday morning I happened across one of New York City’s significant, yet still unassuming landmarks. Just before the corner with 53rd street was a sign hanging from a theatre awning and bearing the distinctive yellow and blue legend: “LATE SHOW with David Letterman”.

For a New York district bound by its reputation for earnest theatricality, not to mention the garish hustle of Times Square at its southern end, this spot on Broadway has, for the last 21 years, been the bunker for an even longer battle and one of the most intense rivalries in entertainment history.

Here, in what he nightly declares as "the greatest city in the world", a lanky, gap-toothed, occasionally obtuse Iowan has commanded the space known universally to American broadcasters and their lucrative advertising accounts as, simply, 'late night'.

Much like Broadway, late night has become a crowded avenue. Whereas once their was just Johnny Carson and Jack Parr, it proliferated in the wake of Letterman and fierce rival Jay Leno taking over the zeitgeist-hugging timeslot, with the likes of Arsenio Hall, Conan O'Brien in the 'late, late' slot, Jon Stewart's Daily Show, and more recently the Jimmys Kimmel and Fallon, not to mention the plethora of talk shows during the daylight shift.

Over the course of his 32 years at the helm of, first Late Night With Letterman and then The Late Show, when he moved from NBC to CBS in 1993 (itself a source of sensitivity as Leno had pipped him to the job as Carson's successor on The Tonight Show), Letterman has, for me, defined the genre, driven by his motto "there is no 'off' position on the genius switch". 

Go anywhere in the world and you will see the desk, the cityscape background and the irreverent host replicated. It has even warranted the equally as funny spoof series, The Larry Sanders Show, in which Garry Shandling brilliantly explored the neuroses of producing a daily talk show (a mantle passed on to Tina Fey's 30 Rock). It also generated the inspired description for all talk show hosts, delivered by Sanders' fictional producer Artie: "like some goddamn mythological creature – half man, half desk."

Letterman didn't invent the format, but he perfected it into a melange of bedtime levity comprising sharp comedy, big-name celebrity interviews - invariably obsequious - stupid pet tricks, street pranks, studio gags and hot music.

There have been serious moments, such as when Letterman returned from bypass surgery, and when he devoted an entire hour in October 2002 to the dying Warren Zevon - a regular stand-in bandleader for Paul Shaffer. The day after Zevon's eventual death, Letterman paid tribute by having Shaffer's house band  play Zevon's songs throughout the night. It was extraordinarily moving.

When America was attacked on 9/11, the late night shows - much like Broadway - fell dark. It took until September 17, 2001, for The Late Show to return, a comedy show unnaturally bearing the flag for an entire nation still raw with pain.

Without its usually lary opening title sequence, the show opened straight on to a clearly emotional Letterman brilliantly and wonderfully trying to ease America back to some semblance of normality.

"This is our first show on the air since New York and Washington were attacked," Letterman began, "and I need to ask your patience and indulgence here because I want to say a few things, and believe me, sadly, I’m not going to be saying anything new, and in the past week others have said what I will be saying here tonight far more eloquently than I'm equipped to do.

"But, if we are going to continue to do shows, I just need to hear myself talk for a couple of minutes, and so that’s what I’m going to do here."

For 20 minutes or more Letterman gave a more impassioned and heartfelt expression of what had happened than I'd seen or read or heard in any speech or newspaper. It remains today one of the most emotionally charged pieces of television I've ever seen. (see Ten Years On).

Letterman nailed it for America that night, but the poignancy was stronger due to the location of the Ed Sullivan Theater, just a four-mile hike down Broadway to Ground Zero. For that night, Letterman shared with Mayor Rudolph Guuiliani the responsibility of wearing New York's heart on their sleeves.

Letterman's announcement, on April 3, that he was to retire from The Late Show sometime in 2015, didn't come as a great surprise, however, to some seasoned late night watchers.

With Leno bowing out last year from The Tonight Show, and the likes of Ellen Degeneres, Stewart, Stephen Colbert, Chelsea Handler, Scotland's own Craig Ferguson and Birmingham-born John Oliver, Kimmel and Fallon all adding fresh impetus to the water cooler-dominating chat show circuit, the buzzards were circling over the late night veteran.

Letterman turned 67 just last Saturday. That still seems to be awfully young in television terms to be retiring. But, then again, Letterman has always done things on his own terms. His gentle on-air ribbing of the CBS network and its president Leslie Moonves, has masked the bitterness with which he lost out, like a sibling losing out on an inheritance, when Carson handed The Tonight Show to Leno.

But now it's Letterman's turn to pass the baton. Comedy Central's Stephen Colbert has been named as  successor when his retirement takes place next year, promising to bring his wry, satirical take on the world to the broader entertainment canvass of late night network television. The shoes he's filling, he won't need reminding, will not be very big indeed.