David Letterman's last stand: 'The more love you show him, the more he'll show you back'

Nearly 60 years after Elvis Presley changed the direction of western culture by miming along to Hound Dog to a mob of screaming girls, a page is reminding the crowd for the umpteenth time that no photography is allowed at the Ed Sullivan Theatre. This is a disappointment for all as they’re coming for their own piece of history: a seat at a taping of the final season of The Late Show with David Letterman, the talkshow that has made its home at a Broadway theatre four days a week – with two shows on Thursday – since 1993.

Despite being a Brit who cannot actually watch the show in my home country and occasionally even has trouble getting clips to play on YouTube, I know how big a deal this is. I know how important Letterman’s show is in the fabric of American TV, of how many Americans fall asleep in front of it each night and then talk about it the next morning. I’m aware of its controversial birth after Letterman was gazumped by Jay Leno for the job once held by Johnny Carson. I know that when Letterman stands down at the end of this year he will be replaced by Stephen Colbert. I know that it matters whose talkshow is watched more, who cracks the best jokes in their nightly monologue and who gets the best guests. I also know that the toilets at the Ed Sullivan Theatre will not be open during recording and I have five minutes left to take advantage of them.

When the doors of the theatre finally open, the impression is quite miraculously underwhelming. On television the Late Show looks like it’s being filmed in the most glamorous ballroom, one that’s somehow both in the middle of Manhattan and on the Hudson river (it has the Brooklyn bridge coming right through its windows). In reality it’s a dingy, dog-eared auditorium whose great vista is actually just a canny assembly of plywood and fairy lights. Dave’s desk is poky, the chairs his guests sit on look like they’ve been bundled in from Ikea. The only detail that matches the ballroom of my imaginings is the floor, which is being brought to a dazzling sheen by a team of dedicated buffers.

The woman sitting to my right, in her 50s with a tight perm and a voice that sounds like George’s mother on Seinfeld, points out that I should not be disappointed. “What do you expect?” she says. “It’s show business!” She then goes on to observe the sheer number of people working on set and that they’re all unionised.

The warm-up comic, Alan Kalter, comes on and picks up a theme stressed by the pages; the importance of audience applause. We need to applaud the band and any solos they might play. We really need to applaud the guests as they come on. As for Letterman himself, we need to applaud his entrance and applaud his jokes, even – or perhaps especially – when they’re not funny. But just as I’m beginning to actually forget the first five injunctions to applaud, Kalter applies a little coda. “It’s important you show Dave all the love you can,” he says. “Because the more love you show him, the more he’ll show you back.”

When Dave bounds on to the stage with an athleticism that, even 20 years ago, Jonathan Ross could only dream, Kalder’s remark makes complete sense. This is showbusiness all right and from the first minute Dave puts on a real show. After running around a bit he collapses on to a camera and starts chatting with the crowd. They ask him questions about his favourite racing drivers and his current opinions on Indianapolis. He makes jokes about the rain and says when he was snubbed by NBC as Carson’s replacement 21 years ago he came to CBS on one condition: “That we do the show indoors.” After a while he stands up again and starts swinging his microphone like Roger Daltrey. He is majestic.

When the time comes for the show, the energy continues unabated. Dave’s monologue is a winner from the off. On the day after the midterm results he opens with a remark on the weather. “It’s 53 and gloomy”, he observes, “like President Obama.” He weaves in references that only the crowd would get and they love it. He does a top 10 (a staple of the show that dates back to Letterman’s NBC days and is nearly 30 years old) about descriptions of food that might put you off eating it. Number one is “freshly exhumed”. The crowd needs no encouragement to applaud.

The mood throughout the Late Show’s hour-long recording is one of ebullience, of talent enjoying the chance to show off. But there’s a poignancy in the air too. There are wry remarks about the show’s age and its rubbishness in the face of modern competition. “Then we’d have a show” is a recurring refrain as Dave thinks of a gimmick that might make things better. The guests – Whoopi Goldberg and Jimmy Page – are inclined towards looking back too. Goldberg recalls a political age when things were less rancorous – “People seem to have forgotten that it’s possible to be friends with people you don’t agree with”; Page, understandably, harks back to the days of Led Zeppelin’s pomp. “That was the thick of it right there,” says Dave.

Letterman has an acerbic humour, but one that’s underlain by a genuine warmth. He has a swagger, an onstage arrogance, but one that’s surpassed by his willingness to mock himself. By comparison, the young buck Jimmy Fallon (he’s 40), is impish and silly and interacts with his guests, not by exchanging zingers but persuading them to take part in games. It’s a different style, one more suitable for the modern celebrity age. You get the impression it’s also something Dave couldn’t adapt to if he tried. It’s the end of an era in more ways than one but as Dave leaves the stage to yet another unprompted round of howling and whooping, there’s still a sparkle in his eye that Elvis would recognise.