Bar few, the eminent figures of the arts world over the past decades have had one thing in common: they’ve all been interviewed by Melvyn Bragg. It really wasn’t much of a surprise then when Bragg’s apology for keeping me waiting at his ITV office was because he’d been busy organising an interview with Victoria Wood.

The Cumbrian culture vulture is host and editor of TV’s longest-running arts programme, The South Bank Show, now in its final comeback series called Revisited. The programme has brought writers, actors, musicians, dancers, directors and artists into often surprisingly sincere close-up. He’s chatted to Laurence Olivier on his deathbed; he chased the French composer Olivier Messiaen for twenty years; and George Michael marked the occasion by lighting up an enormous spliff. In addition to the show’s unparalleled duration, Bragg can also claim credit for his role, as he puts it to me, “in tackling opera and pop music with equal seriousness”.

‘Oxford and the movies were where my whole life really started’

But above all there is his gift for disarming some of the trickiest and most fortified egos on the planet. Finding that parenthesis, getting that foot in the door to the mind of the interviewee must be a real challenge? “Yes. You’ve got to get it right. The point of entry; that’s the really the hard bit”. Most people, he tentatively explains, start out looking like they’re shot through with nerves, jittering apprehensively. “Not about me, or my questions”, he’s quick to add, “but because they’re on screen; it’s very different from the way you talk to your pals, or even the way you talk on radio. You know that your face is going to be in other people’s faces”. Bragg pauses. He seems slightly hesitant. “The way you look counts for a big percentage of the way people see you, and they know that.”

Even so, Bragg always seems to pull it off and lay bare the raw talent of creative minds. In the astonishing Francis Bacon interview, he and Bragg go out for lunch and get absolutely plastered on disgusting red wine. Bacon staggers to his feet, declares “Cheerio”, and fills their glasses again. Bragg asks: “Why do you want to do that, Francis?” The artist replies: “Because I like doing it. I just happen to be a painter, that’s all.” He then goes on to talk eloquently, if a little slurringly, about his work. “Francis drunk was a very important part of Francis”, Bragg said. “And when he was drunk he talked about his life to the highest level.”

Most famous of Bragg’s encounters was his interview with Dennis Potter in 1994 just before his death where he started with the question: “How did you, and when did you, find out that you’d got this cancer?” The interview rocketed round the world and people took to it because of the power of what Dennis said, and because of the way they did it: Bragg vividly describes the shabby, stripped down TV studio where Dennis was sipping liquid morphine, clasping a bottle of Champagne and heavily smoking.

Asking Potter about his cancer was a one off though. Bragg’s main focus has always been on the work of the artist, not on their personal life. It’s the quest to get to the heart of “what is real in the marrow of their work” that he sees as the definitive challenge. “Sometimes I get it and just feel rather quietly pleased with myself”.

He candidly admits that the personal does occasionally seep in, like when Bacon talked about his homosexuality. “But he brought that in”, Bragg assures me; “I didn’t sort of say are you gay or anything”.

I learn that keeping this sense of distance from people’s private goings on is a belief instilled in Bragg by his small town background – it’s something quite necessary in a tight-knit community, he points out. “You really mustn’t pry into the private lives of others”.

Part of this belief might also stem from the great personal tragedy he has had to come to terms with. His first wife, the French writer and artist Lisa Roche, committed suicide in 1971, a pain that he has said “never stops”. In 2008 he published the novel Remember Me… that addressed her death in fictional form. It took him almost five years to complete it, “rewriting and rewriting. I worked harder than I’ve ever worked at anything”.

It was Bragg’s 20th offering in a long pedigree of novels and it dug into the last part of the previous novel Crossing the Lines; the two form “the Oxford novel I refused to write”. But although part-fiction, the passages about Oxford had to be written. “They were where my whole life really started.”

So what’s the reality behind Bragg’s Oxonian turning point? “There were some crackingly good Historians to look up to”, he says. But it was the allure of the movies shown at the Phoenix Picture House in Jericho, then named The Scala, which really changed everything. “Something clicked. I saw that there was a different world out there.”

He explains how he became immersed in contemporary European film, enthusiastically reeling off an endless list of directors I’ve barely heard of. By his third year he’d moved a long way away from just wanting to pass exams. He was enjoying writing for Cherwell as film critic, acting, and had even tried his hand at writing short stories, “although I sure didn’t tell anybody”. He also loosely remembers co-directing a film at Oxford called Altogether Boys. I eagerly press him for a copy. “Mercifully none of us know where it is!”, Bragg responds.

He went on to win a traineeship with the BBC, “and that was probably the biggest stroke of luck in my life. In retrospect, I’m rather embarrassed to say, at the time, I hadn’t a clue what I wanted to do; I genuinely had not a clue”.

But Bragg moved up the ranks quickly. After a 10-year stint on Start the Week, which he turned into a Radio Four flagship, he launched In Our Time, with the county’s top boffins talking it out about anything from Platonic philosophy to the frontiers of contemporary physics. “In academia, a lot of it is taken for granted. My job is to say, hold on, I didn’t understand that Higgs boson”. He thought it would probably only last six months. Instead, it has become a benchmark of quality broadcasting and he tells me he’s just signed another three year contract. “I’m up at five am doing my final cramming session before I go in”, he tells me. “That really keeps you going”.

Now in his 70s, Bragg has more than a lifetime of experience to retell. But could he see himself being interviewed on The South Bank Show as the great populariser of the arts that he now is? “Oh no, wouldn’t dream of it.” As Bragg modestly puts it: “I’m not a very good interviewee actually”.