In a mocked-up Main Street in the middle of a field in Sussex, several strikingly well-dressed women are queueing impatiently for admission to the catwalk show in the Fashion Pavilion. Some are clad in the khaki uniform of the First Aid Nursing Yeomanry (the famous Fanys), some are in land-girl slacks with their hair knotted inside red bandannas. Others are squeezed into tight rayon skirts that accentuate their Monroe hips, or floral cotton blouses with embroidered trim that their grandmothers might have considered a little fussy back in 1948.

Run your eye along the line of beauties, and you notice not everyone has gone for a Forties theme. Mad Men-style floral frocks with belted waists from the late 1950s are popular. Hobble skirts and polka-dots are everywhere, as are white gloves and teeny hats, like sequinned skull-caps clamped to the side of marcelled heads. Sixties-chick paisley mini-dresses compete with white PVC coats and Courrèges boots for the title of Most Authentic King's Road Look Circa 1966. There are even some boob tubes and fluorescent leggings from the 1980s, worn by skinny teenagers – to whom, of course, they represent the quaintly old-fashioned style of their parents' generation.

Not everyone is waiting for the catwalk show in this huge field in the grounds of Goodwood House. On the main stage, 500 yards away, the retro-rocker Alvin Stardust is knocking the crowd dead with "My Coo Ca Choo", unheard on the airwaves since 1973. A DJ called Simon the Preacher is manning the ones and twos in the Let It Rock tent, while a sextet of white, urban, soul-jazz-funk exponents called The Filthy Six are conjuring the old 1960s Blue Note sound on the Soul Stage. Devotees of British cinema are catered for with a 2pm screening of the Ealing Studios classic, The Lavender Hill Mob and, in the Tanqueray Torch Club, chaps in ginger moustaches and their petticoated lady friends are jiving to the boogie from the delectable Laura B and the Moonlighters.

Welcome to the world of Vintage, the style revolution that's been sweeping the nation for a few years – a counterblast to the domination of designer labels and high street convention – and, more specifically, welcome to Vintage at Goodwood, the inaugural music-and-clothes festival on the Duke of Richmond's estate near Chichester, West Sussex, managed by his son Charles, Earl of March. It's a massive enterprise, spread over three days and involving music events, fashion shows, art installations, classic English movies, vintage cars, a fun fair, a circus and an astonishing number of visitors unselfconsciously dressed in crêpe frocks and plus-fours.

Goodwood has been a name in the festival diary for some years for its annual Festival of Speed (racing cars) and its Goodwood Revival (vintage cars, 1940s-60s). This is the first time it has embraced rock'n'frocks. "When we started the Revival," says Charles March, "what amazed me was how directly people became involved with it. We wanted to see if we could use it in a different way, to create something a bit edgier, more arty and cultural, to bring music and fashion together. For me, one of the most exciting things is that the people become the show."

He formed a partnership with Wayne Hemingway, the designer behind the Red or Dead label, who, with his wife, Gerardine, masterminded the look of the festival. "There are lots of vintage weekender festivals," explains Hemingway, "which celebrate a single niche – rockabilly, say – and they're usually held in grim seaside resorts. This festival brings everything together. We wanted to celebrate the gamut of British creativity – music, fashion, art and design, film, food – and give people a chance to dress up and be glamorous. The coverage has been fantastic. El Pais [the Spanish newspaper] said we had built 'a city in a field'. Not quite, but we've done a lot more than put some burger vans in a muddy meadow."

Indeed. The festival's centrepiece is the Main Street, down which punters stroll, gazing at the two-storey façades on either side. There's a miniature Fortnum & Mason, a bonsai Veuve Clicquot, a mignon Bonhams auction house (where pop-culture memorabilia is going under the hammer, along with some jewels once owned by Jacqueline Onassis). Mocked-up bars feature trompe l'oeil pictures of knitting-pattern models posing in the windows. An early portrait of the Rolling Stones in about 1962, looking pleased as Punch in their sensible new grey suits with fur collars, dominates the skyline.

The Main Street idea came from Hemingway's son, Jack. All his family seem to have been involved. Jack's mother masterminded the festival design, while other Hemingway siblings contributed their two penn'orth. Tilly Hemingway, a vision in a cappuccino-and-cream shirt and banana-hued beret, designed the frontage of the VIP Lounge in three days with the help of a computer.

"We came up with the idea of a vintage festival three years ago," says Hemingway. "I knew Charles March because of the Revival and I always loved Goodwood's attention to detail. Charles knows all about houses and cars of course, but he's a very cool guy and he's really into music." They went into a 50-50 partnership: la famille Hemingway to look after the content, and Goodwood to handle all the logistical delivery. "I couldn't do what he does. A team of designers couldn't have done all this" – he waves a hand at the pullulating thoroughfare crammed with walkers in ancient silk frocks and an artfully decorated Routemaster bus apparently owned by Sir Peter Blake. Both men seem to have a hand in choosing the music, which includes a reunion of The Faces, with Mick Hucknall standing in for Rod Stewart on vocals, and Kid Creole and the Coconuts.

Outside the Demon Drome – an authentic 1920s fairground Wall of Death complete with grizzled leather-clad riders who can roar horizontally around the circular wall side-saddle, doing 60mph with their T-shirts over their heads – a chap is showing off his penny-farthing bicycle to some children. The catchment area of "vintage", it seems, extends back well before the last war. To many sceptics, all it means is a generation of people who haunt charity shops because they can't afford the prices in Topshop. To others, it's a return to a well-integrated look of sophistication, from Victory rolls to seamed stockings, by way of coral lipstick and elaborate maquillage.

"How do you define a vintage look?" asks Charles March, who is resplendent in a 1972 fawn velvet suit from Huntsman in Savile Row. (It did not come from an Oxfam shop. He owned it back in 1972.) "It's got to look as if they're your own clothes and you're comfortable in them, rather than look as if you're dressing up." Wayne Hemingway is more severe. "Some people come dressed as hippies," he snorts. "Or appear in a stupid Elvis wig. I mean, they stand out a mile. That's not vintage, it's just fancy dress. They just don't get it, do they?"

In the cars encampment, where a magnificent 1950s Cadillac Coupe de Ville basks in the sunshine, I meet a virginally pale young woman in a 1950s red polka-dotted swing dress with a black gardenia in her hair. She is Hannah McCarthy, a purchasing manager for a boiler-making company in Poole, Dorset. So does she often dress up in the style of a more innocent era?

"All the time," she says shortly, batting her massive, false eyelashes. "I'm a burlesque performer."

Ahem. You mean you...

"And a striptease artist. And a pin-up model. Here's my card." I note from the card that, when not supervising the purchase of boilers, she goes by the name of Miss Fan-Teasy and gets her kit off regularly in Bournemouth.

"I love vintage festivals. I love the way everyone dresses up," says the mistress of un-dressing. Through her I'm introduced to Mr Tony Nylons (possibly not his real name), who is the publisher of a magazine called Glimpse that's filled with young gels revealing their petticoats, adjusting their stockings and looking faintly minxy in black corselettes. Miss Fan-Teasy features in its pages, starting off in motor-mechanic overalls, which she soon sheds in search of something cooler.

You soon discover that burlesque – mild, peek-a-boo soft porn with ladies in ostrich feathers and outsize foundation garments – plays a major part in the vintage world. It's as if the female aficionados, having adopted the sculpted hair, the cherry lips and make-up, the classic frock, the stockings and stilettos, will naturally wish to show off their undergarments to the outside world (or, at least, to an audience of pipe-sucking squadron leaders).

The gentleman's version of the be-stockinged lovely is the plausible spiv. The festival is populated with fine examples, none more charming than Viv the Spiv, who hangs around the Tanqueray Torch Club. He wears a double-breasted zoot suit with a handkerchief poking from the breast pocket. A purloined HG (Home Guard) badge, co-respondent shoes and a tie featuring a lady of loose morals, all indicate that Viv may be an absolute bounder. He's certainly a comedian. "See this tie? They don't make 'em any longer. Well, if they made 'em longer, they'd come down to 'ere, wouldn't they? The other day, some bloke offered me 200 nicker for this tie. Speaking of knickers, I got some out in the car. Lovely they are, made from German parachute silk. I call 'em Messerschmitt knickers, 'cos they go down without a fight. 'Ere..."

It's a slight let-down to discover that, in Civvie Street, Viv is a plasterer whose real name is Iain Dawson. But you soon discover that a fair percentage of the best-dressed vintageurs are part of the business: married to one of The Swing Commanders café orchestra, say, or members of The Royal Harmonics, a group of middle-aged a cappella performers who sing Queen's "Don't Stop Me Now" with expression in the middle of Main Street.

Here are some real people, however, in the Tanqueray Torch club, where the John Miller Orchestra is playing graceful swing: meet Chris and Tracy from Canterbury. He is stern-looking in a blue USAF pilot's uniform; she is resplendent in a fur stole over a tight black frock. A lot of thought has gone into their look, which is of a shameless British housewife, out on the razzle with her Yank boyfriend while her husband's away fighting overseas.

"We love all the dressing-up," says Tracy. "I get my clothes from My Old Dutch in Margate." She and Chris travel the country in search of a decent hangar dance. "The next is Twinwood," she says, eyes shining. She means the Twinwood Festival of Swing, Jazz, Jive and Rock & Roll, incorporating the Glenn Miller Festival in Bedfordshire, although there are plenty more at which to perfect your lindy hop before the end of the year.

Clouds are threatening at 4pm. There's an uncertainty in the air, about whether to stand in the rain to watch Roy Wood (songwriter with The Move and Wizzard, the man behind "I Wish It Could Be Christmas Every Day") on the main rock stage, or queue for the shelter of the tea-dance indoors. Among the ladies making up their minds are a striking pair, Harriet and Jenni. The former is a fatale blonde in a blue satin dress and a fur stole, the latter a Polish-Japanese gamine in a magenta frock and black gloves. Both in their twenties, they are serious women with a well-developed sense of frivolity. Jenni, from San Diego, recently moved to London, "and I've a whole wardrobe of vintage frocks, so this is heaven for me". Harriet lectures in human rights law at Brunel University, and habitually arrives at the lectern wearing vintage threads: "My students love it," she coos.

By Sunday afternoon, things have become slightly unhinged. At the extremely silly Chap Olympiad, organised by the stolid burghers of The Chap magazine, gentlemen in George V beards and ladies in Duchess of Windsor sunglasses compete to see how far they can throw a plate of cucumber sandwiches. The magazine's resident whiskers expert, Michael "Atters" Attree, presides over a Chaps vs Chapettes tug-of-hair. "Could some fellows drop out voluntarily to make it easier on the gels?" asks the umpire. This retro-Edwardianism is not strictly vintage, of course, this is more about dressing up as a John Buchan hero (eg, Richard Hannay in The 39 Steps) and mucking about in a pipe and side-whiskers. But one hardly feels like complaining – especially not during the Three-Legged Trouser Limbo Dance.

Around the field, representatives of The 1940s Society loll about in uniform, like a squadron waiting to scramble. In the Car section, a septet of bathing beauties inspects the Vespas and Lambrettas with their extravagance of headlights. Beside the funfair, young girls in Pink Ladies sweaters (from Grease) queue for Pimm's at the window of a London bus while, inside the Dodgem rink, the roller-disco fans progress round and around, their faces set in a mask of imperturbability.

Was it all about becoming drenched in nostalgia for a weekend? "Vintage is about looking forward through the window of the past," says Charles March. "It's like when you look through a photo album of your parents, and see your mother with a beehive and become inspired by that. You might listen to Goldfrapp and hear how she's inspired by Donna Summer. You can do the same with fashion. Did you see the queues for the Future Vintage show? You can look at future fashion and see how it was inspired by Ossie Clark or Zandra Rhodes."

But wasn't it extraordinary, to think how many British girls have been inspired by Oxfam shops? "The British have always been brilliant at recycling," says Wayne Hemingway. "You won't find Italian or French girls doing that. Or should it be 'upcycling'? Young girls taking an old piece of cloth and doing something creative with it. It's not about hugging the past – it's about mixing old and new. You see that dress over there? With the bag and shoes? They'll look good in 100 years' time. That's the whole point."

Comments