At the head of the desk Tarrant - 46, shock of old-gold hair, big and baggy ham-coloured face, slightly surprised eyes, the permanent and purposefully relaxed look of a satisfied man in a cigar commercial - leans back into his chair, prodding into place the tape cartridges which punctuate the show. There are 200 racked up beside his desk: they have been wheeled on at the start of the show and their labels - Yippee], Happy Monday, Caine - distinguish the sound and feel of Tarrant's breakfast show.
The music starts. Capital FM is, remember, the station where the listeners have elected George Michael's Careless Whisper as the top record of all time: the music is for those who would disparage the MoR label but are happy to be told that the Doobies singing Listen to the Music, which is what Tarrant now has them doing, is a classic track.
Tarrant hums odd snatches of the record as he lines up the next on the turntable ('Look] Real vinyl] All the edges of these records have been worn thin by DJs spinning them back and forwards to line up the start) and Kara does a backing singer swoop-and-dive obligato at her end of the desk.
The same every morning, five days a week, three hours a day, 44 weeks of the year. 'The night before I did the first show in 1987 I went to bed at 8.30 like a good boy, lay there like a prat for a couple of hours and then went over to the pub. I just don't need that much sleep. Now I've got this early morning stuff down to a fine art. A nice man from Capital rings me at 5.45 in the morning and says are you up, I have a bath and all that, and it takes me 20 minutes to get in from Esher at that time of the morning.
'Funny thing is that I have no concept of a rush hour. I sit here listening to the reports about hold-ups on the Robin Hood roundabout every morning, but I've never seen one.
8am: From inside the studio the show has its own odd rhythm - one moment bright and pacy, as if building up to something important (except that importance is the very antithesis of a breakfast show's rationale) and then for the next quarter of an hour just shuffling along from ad to ad and record to record.
In one of the lulls Kara has laid her makeup out on the carpeted desk and is making big eyes into the mirror on her powder compact. Next to the make-up brushes is a little pile of pills - vitamins, mineral supplements, whatever keeps you going every morning at this time. 'Guarana anyone? she shouts, picking up a dun-coloured lozenge. No takers.
'Drugs, says Tarrant. 'That's how I do it. Write that down. He grins the leering-boy grin that comes out on all those TV voice-overs even when you can't see the face.
'Nah. It's not drugs. I went over to the States and I was a sort of guest of the day on all these stations. Christ, but the amount of coke they do. It's really worrying. What a way to go, eh? Angie passes him a tube. He looks at it dolefully. 'Look what I get. Sugar-free mints.
'When I started this, Noel Edmunds said to me that nobody could do a breakfast show for more than a year, two years maximum. But I've been here since 1987 and it's fine. I still get the buzz. They offered me the Radio One Breakfast Show four years ago, offered to match the Capital contract, all of that. In the end I didn't go. I mean there's no need for a national station like Radio One, is there? When I hear Radio One telling me about a traffic jam in Falmouth I think, what's that got to do with me? London is the best place to work: there's an extraordinary range of people who listen to me. It's not just the Jack-the-lads in Bethnal Green waking up with their girlfriends; there are a lot of ABC1s out there. The show has a weekly audience of 25 million.
8.50am. Tarrant has just taken the plastic wrapper off his second large cigar and it hangs limp from his lower lip like an oversized Woodbine.
Everyone in the studio smokes, and the smoke curls round the room. Someone called Ollie phones through to Kara from some other part of the building with details of an extra traffic jam. 'Movers Lane fly-over? Yes, I've got that one darling, she says, tapping her touch-screen. 'Super]
Tarrant taps in a cartridge - it is Michael Caine telling us that he's been asked to say something nice about the programme but can't think of anything nice to say, and while he says it, Tarrant nips round to rearrange the white-board on which are scrawled the morning's requests and dedications from Kent and Surrey and from offices in W1.
It's a very English sort of show - no Smashy and Nicey mid-atlanticism here. 'Some of the jingles have become a bit American, says Tarrant, 'but that's all. This is a local radio show and the whole point of a local radio show is that it should sound local.
Howard Hughes, a lanky peripatetic radio voice, rushes in with his half-hour news bulletin treble-spaced on sheets of white paper.
'There's no news today at all. I have to keep on writing the same stories over and over.
Tarrant winds him up about his clothes, his voice, his script until the very second that the station ident and the news tag is pushed into the cart and Hughes reads his script, tossing each page over his shoulder as he gets to the end of it.
9.15am: Tarrant doesn't have to worry about whether there's any real news or not: the grist to his mill are the little news-in-briefs that fill up the papers in between the real stories. Throughout the morning Titch passes him sheets of paper with clippings from the morning's papers neatly stapled to them. 'There's a bloke in Melbourne going round asking people the time - until he finds the watch that was nicked from him.
He rattles of the stories with a just-fancy-that weariness which suggests that while he recognises that there's nowt so queer as folk, even he is amazed the lengths some people will go to get their name in the papers. Although he started his working life as an East End schoolteacher, skint and sleeping in a minibus, Tarrant was once a broadcast journalist in Birmingham on the local news slot. Other journalists got to do the fires and the police chases: Tarrant gravitated towards the 'And finally. . .' knock-about slot.
That became Tiswas, the Saturday morning kids' show for adults, first in the Midlands and then nationwide, with the up-and-coming Lenny Henry and Bob Carolgees.
Tarrant parlayed that into OTT, the anarchic late-night adults' show for kids, with Helen Atkinson-Wood and Alexei Sayle, and although the show proved only that cult viewing can come through luck rather than judgment, he finished up as a fully-fledged TV face.
'Radio's much, much more fun than TV. I just drifted here to do a Sunday show once, and at the end I said 'Is that it?' You can turn up here 10 seconds before the off and just do it. But then I'm a very make-it-up-as-you go-along sort of bloke. What you're getting on the air is what you'd get if it was just you and me. The other thing is that you can be far more over-exposed on the radio.
Which is true enough, for it is generally acknowledged in the business that in the 30-odd TV quizzes and game shows he has done since Tiswas, Tarrant has never really found a TV format which has made the best of him. 'I won't let the job impinge on my life. Tarrant's life is his home and family in Surrey and his fishing. He is fanatical about angling.
9.55am: The next shift is about to come in. As Tarrant starts to sign off, the incoming DJ stands by his shoulder and they do a quick bit of Smashy and Nicey banter while Titch wheels off Tarrant's carts and brings the new set.
Tarrant walks down to the canteen. 'It's not true that I've never seen a traffic jam at the Robin Hood round-about. I once had to drive in at 9am and they said, 'give yourself a couple of hours'. I said, 'what are you talking about?' but they were right. I couldn't believe it. It's screaming mad out there, which is why people listen to us.
'This show probably saves people's lives.
Chris Tarrant is on from 7am till 10am, Monday to Friday on Capital, 95.8 fm.