So who's the mastermind behind a TV success?

Jon Magnusson's big sister, Sally, is a staple presenter of BBC Scotland's nightly news programme Reporting Scotland, in Glasgow. She also somehow finds the time and energy to be the mother of five children.

Margaret Magnusson has recently returned to work with the BBC in London, following the birth of her fourth child. She is a freelance producer of TV news features and documentaries.

Anna Magnusson is a senior radio producer in BBC Scotland's religious department in Glasgow, working chiefly in the documentary field.

Siggy Magnusson, Jon's elder brother, died at the age of 12 in a road accident.

FOR the five Magnusson siblings, offspring of renowned journalists Magnus and Mamie, childhood Friday nights at the family home in Glasgow's rural hinterland were always memorable occasions. Hilarious. Exhilarating. Joyfully hectic.

First, the young quintet would be whisked off to an enjoyable series of piano lessons. They'd next be treated to fish suppers, before settling down for the pre-bedtime telly highlight

of many a seventies adolescence, Morecambe and Wise.

It's thus entirely fitting that the youngest scion of the Magnusson clan, Jon of that ilk, should have grown up over the succeeding 25 years to play a vital current role in mirthfully illuminating this nation's Friday nights before the gogglebox.

So, Jon Magnusson. So Graham Norton - how did you wind up producing Channel 4's naughty Bafta-winning Friday-night delight, and how does your family view your giddy departure from the more serious Magnussonite tradition of broadcasting?

''I'm aware I'm the only rude, fluffy, showbiz light-entertainment person in a family of proper journalists, but they're all very nice about it,'' says Jon, whose accidental post-graduate route into TV began musically in London 15 years ago via the provision of piano accompaniment on sundry Radio 4 comedy sketch shows.

''In fact, my mother enjoys watching Graham every week, which proves that he's the show's unique ingredient. Because there's no getting away from the fact that the show's filthy by any standards, and yet Graham draws all sorts of people, from all age-groups. He's become a national institution. We can't get over it.''

In particular, the team at So Television Productions can not get over a recent not-guilty ruling from the Broadcasting Standards Council. ''They adjudicated on a show in the last series,'' says Jon. ''No phone complaints had been logged on the night about the particular item, but someone had notified the BSC direct.

''Admittedly, at the time we made the show we were thinking to ourselves: 'We are perhaps pushing the boat out here by having a webcam running throughout this one'. So as soon as the BSC became involved, we all thought: 'It's a fair cop, we'll lose - it was filthy.' ''

Filthy is perhaps an understatement. Indeed, the mucky pups of So were sufficiently convinced of their impending BSC censure that they'd gleefully envisioned being required to end a show with a po-faced disavowal of their heinous crime.

Suitably sombre voices had therefore been tested in So's Covent Garden offices. A penitent script had been rehearsed. Interrupted by anticipatory chortles of hilarity, it would have gone like this: ''Channel 4 wish to apologise for a recent edition of So Graham Norton in which a Hungarian lady played the national anthem on a penny whistle inserted in her genitalia.''

Blow me if any of today's plethora of TV chat show hosts could get away with that malarkey without giving offence - and be commended by the complaints watchdog for having ''a charming manner'' into the bargain. Not hectoring points-scorer Jonathan Ross. Not laddish, nasty Frank Skinner. Not dull old Parky.

The fact that Graham Norton invariably succeeds in being positively

foul is largely down to his talent for self-deprecation, the Irish twinkler frequently describing himself as a ''gaudy poof'' after all. It's also thanks to the genuine air of arm's-length

bafflement, dismay, and moral disgust with which he peruses each new

confession of sexual or behavioural deviation on his show.

It does rather help that Norton's a singularly funny comedy performer, too, of course, having honed his winning way with an audience through years of work on the live stand-up circuit. But this would all count for nought if Graham Norton weren't in the right TV setting.

Another Graham of Celtic descent, Dundee laddie Graham Stuart, should therefore be commended for quickly realising that So Graham Norton needed Jon Magnusson's skilled comedy hand on its tiller.

Who's Graham Stuart? He's So Graham

Norton's executive producer and co-creator. Scottish football fans with long memories might recall Graham Stuart in his fresh-faced youth, incidentally, when he spent a year on STV's Scotsport as Arthur Montford's sidekick.

Rangers brutish manager, Jock Wallace, once gave Stuart unforgettably short post-match shrift on the Ibrox touchline. On another occasion, delicate viewer sensibilities were outraged when Stuart appeared on screen wearing shoes that had been besmirched by the mud of Hampden's car park.

Stuart's a much more polished TV pro now, though. Why, following the show's so-so first series, he wasted no time rectifying what was missing. Enter Jon, with a solid CV as a comedy producer. There was When Harry Met Ally on radio with Harry Hill and Alistair McGowan; TV work with Mel Smith and Griff Rhys Jones; the original spoof American TV chat shows ads for Miller beer, and lots more.

''When the two Grahams approached me I was very keen to work on a chat show,'' says Jon. ''I'd had great fun writing and directing the Miller beer Millertime ads, which were basically three-minute parodies of The David Letterman Show.

''The first So Graham Norton series had looked interesting, rather than being an immediate success. Graham Stuart is a great chat-show producer - he knows the chemistry of guest bookings and the rhythm of chat. My job is to look at

Graham Norton as a comedian, not as a host, and let him score comedy points.

''So we go for guests Graham has an interest in, and who will play along at comedy with him, something which gets us off the standard round of professional guests. I also don't like chat shows with music breaks, or music guests - despite the fact that I'm a musician, and set off in life to be a jazz pianist.

''Nor would I ever let my host sing at the end of a show - although that said, Graham did have singing lessons before we went out to Dolly Parton's theme park, Dollywood. That was for one of two special Christmas travelogues we've done this year, with the other in Mexico.

''At the end of Graham's week with Dolly, he sings Islands in the Stream with her, floating alongside in a rubber ring - in a stream, naturally enough - surrounded by floating Dollywood employees. Graham's tone-deaf, and so I can honestly say that it's an extraordinary musical performance.

''Graham's real comedy strength is in working with both the studio audience and the TV audience. The studio crowd aren't there merely to provide a laughter-track. Graham melts them, getting them to take part. He makes a real emotional investment in them.

''They're made to feel happy with themselves. Via our on-the-night questionnaires, he discovers things about them. They become his foil, a recurring comic device.''

Jon has had plenty of first-hand performing experience himself, most of it musical. After Glasgow Academy and Eng Lit at Oxford, Jon spent two years as a session jazzer, working mostly on incidental music for radio shows. In his teens he wrote and starred in Goldoni, an Edinburgh Fringe youth theatre musical about the eighteenth-century Venetian playwright.

However, unlike Jonathan Ross's producer, Andy Davies, an uneasy-looking on-screen component of Wossy-boy's present lacklustre BBC rival to So

Graham Norton, Jon won't be appearing alongside his charge. ''When I first began producing radio light entertainment shows, I had to warm up audiences, and I soon realised I can't do gags.''

Jon learned other important lessons from two men he respectfully refers to as ''the Guv'nors - Mel and Griff. ''They saved me by taking me to Talkback, their production company. They saw some

talent in me, and they supported it. They also taught me how to write comedy.''

Jon Magnusson's longer-term future? For the moment it's bound up in that of So Graham Norton, which looks to be imminently westward-bound across the Atlantic. ''American TV has become keen on Graham lately, and it would be nice to think I could make the break over there with him.

''I'd love to work in America. Belatedly, I've become a big fan of travelling and of New York. Maybe because my dad used to travel so often, chronicling the world, I preferred staying at home.''

The only thing preventing So Graham Norton's full-time export to the States, it seems, is the show's high filth content. A prudish lot, Americans. Long may their loss be our gain.

So Graham Norton's five-season-long domination of Friday night TV chat show comedy continues on Channel 4 tonight at 10.30pm.

The Magnusson Clan

Jon Magnusson's big sister, Sally, is a staple presenter of BBC Scotland's nightly news programme Reporting Scotland, in Glasgow. She also somehow finds the time and energy to be the mother of five children.

Margaret Magnusson has recently returned to work with the BBC in London, following the birth of her fourth child. She is a freelance producer of TV news features and documentaries.

Anna Magnusson is a senior radio producer in BBC Scotland's religious department in Glasgow, working chiefly in the documentary field.

Siggy Magnusson, Jon's elder brother, died at the age of 12 in a road accident.