It starts at two in the morning. I've been to bed - I'm a visitor, after all, unused to the rigours of Carnival. Perhaps it's because the hands on my body clock are spinning in contrary directions that what follows seems faintly unreal: dancing - "chipping" - en masse through Port of Spain in pursuit of a steel band making stately progress to nowhere in particular; smearing and being smeared in mud and paint by muddy, painted devils; limbo dancing badly at sunrise. This is J'Ouvert, the nocturnal orgy that kick-starts the biggest street party in the world.
The devils are "jab-jabs", one of few remaining traditional Carnival characters. It's a tradition, too, that if you're clean, they'll splatter you with a tankard of goo scooped from tin baths wheeled behind the monolithic sound systems that pass through Port of Spain's avenues ripping the air with dins that rasp "stampede!" or "bacchanal!"
"Chipping" is the loose-limbed tramp with which that pageant's disciples give chase. It resembles an exhausted stagger, which is convenient, because even after four hours of "jumping up" and downing Carib beer, I don't look out of place. At daybreak, my gyrations - I call it limbo at the risk of besmirching a cornerstone of Trinidadian culture - clumsily denote an epiphany, that moment when dancing and music have eclipsed and express everything.
"Dance!" novelist Earl Lovelace wrote of calypso and Carnival, "If the words mourn the death of a neighbour, the music insists that you dance; if it tells the troubles of a brother, the music says dance. Dance to the hurt! It is in dancing that you ward off evil. Dance!"
He is true to his word: I saw him at Carnival, dancing. The breadth of commitment to the event is astonishing: that the literati, like Lovelace, and politicians - last year, finance minister Brian Tung was snapped in wild abandon - should want and are able to muck in speaks of a cultural democracy we can only dream of. Compare and contrast to William Hague at Notting Hill.
But Carnival isn't an appendage to Trinidadian life, it is the culmination of Trinidadian life. Here's Lovelace again: "This is the guts of the people, their blood; this is the self of the people that they screaming out they possess, that they scrimp and save and whore and work and thief to drag out of the hard rockstone and dirt to show the world they is people".
I was struck, reading local papers for a week before Carnival, by its monopoly on the news. Who won the Calypso Monarch title (Singing Sandra), whether Trinidad's very own Miss Universe would sacrifice Fashion Week for Carnival (she did), why Carnival gets the army's goat (revellers in uniform) - the Trinidad Guardian held its front page.
You can also gauge the obsession by the preparation: Carnival begins at Christmas. I arrived in Port of Spain at midnight and found the town's social life by cocking my ear to the wind. Follow that tinkling noise to one of many ramshackle panyards; here, the city's numerous steel bands rehearse for Carnival nightly - and all night - to crowds of drinkers and fans. There are plenty of both: the Trinidadian's capacity to enjoy himself is admirable. You know you're in the right place when the keys of your hire car come with bottle-opener attached.
The island's steel-band culture resembles football culture in Britain, except - and this is characteristic of Trinidad - it is creative and participatory. Steel bands, like football, sprang from working-class communities, an expression of their identity and - frequently - rage. Flare-ups between bands form Carnival legend: Invaders versus Tokyo in 1950 (nine injured); Desperadoes versus San Juan All Stars in '59 (30 injured). Recent years have seen Carnival's maverick tradition diluted; like our national sport, it's been gentrified and corporatised. Invaders are sponsored by the national airline. "Play mas", the billboards say, "Drink Coca-Cola". "Mas" means masquerade. J'Ouvert is "dirty mas", the relic of satirical, subversive Carnivals gone by.
At J'Ouvert, the past slings gunk at the present, or "pretty mas", which dominates Carnival Tuesday. It's pretty because Carnival has been inherited - some might say hijacked by powerful designers. It costs the price of a costume - industriously produced in mas camps in the months preceding Carnival - to participate; some banks advertise loans for the purpose. In the words of Peter Minshall, mas designer and orchestrator of the opening ceremony at the Barcelona Olympics, "In most countries, people pay to see others perform; in Trinidad, they pay to perform."
While there are isolated instances of preposterous sartorial extravagance - 10ft tall costumes, supported by wheels, fashioned to evoke flowers, or witch doctors, or frogs - these are exceptions to the prevailing rule, which states: it's Carnival, wear a bikini. On Tuesday, one phalanx after another of flesh-baring men and many more women charge across a vast stage traversing the Queen's Park Savannah, the city's lung and hub of Carnival. Purple knickers wink and sequinned silver thongs thrust; golden bras bulge and fiery red headgear blooms, tropically. Bands keep passing and colours keep intensifying, until your eyes ache, and still it won't stop. The year before last, the biggest band, Poison, had 10,000 members. They took two hours to cross the stage.
I pop outside. Half a mile from the grandstand's cocktail-tinted chaos, I still hear the same incessant tunes.
There's a competition (Carnival is a series of contests) for a song to be crowned "Road March" - usually soca, which is a mix of soul and calypso driven by a heavy beat. Carnival's soundtrack comprises a handful of insistently catchy refrains, looped, and to even suggest what it's like to be there, I'd have to persuade the Guardian to attach an accompanying CD. The pre-eminence of sound systems, at the expense of steel bands - whose involvement peaks at the Panorama competition two nights before Carnival begins - is a symptom of this event's sometimes painful evolution from home-spun fête to international post-modern extravaganza. Even calypso is undergoing an identity crisis.
Veterans worry that wry reflection is giving way to venom: when, at last year's Carnival, calypsonian Sugar Aloes lyrically ribbed the prime minister's wife, both Sugar Aloes' legendary forebear The Mighty Sparrow and the PM, Basdeo Panday, both leapt to the stricken damsel's defence.
By way of personalising that schism between what Trinidad was and is becoming, a local artist named Kathryn Chan - who is curating an exhibition of Carnival artefacts at London's Horniman Museum later this year - introduced me to several neglected figures from Carnival's past.
By the candy-coloured shanty towns of suburban Port of Spain, she drove me to the collapsible house - it was held up by a cactus - of Cito Velazquez. He was the Minshall of his day; his work so impressed Dr Eric Williams that the then PM commissioned him to adorn Port of Spain with sculptures to mark independence in 1962. We later met Leighton James, an unheralded grass-roots artist who has carved an incredibly expressive tableau of figurines representing Velazquez's 1959 Carnival presentation, Flowers and Fruits.
Both men's work is simultaneously poignant and inspiring. While James's fancy-dressed maquettes depict a Carnival that's more specific than today's "bacchanal" to the Caribbean's unique folklore, the circumstances of their creation testify again to Trinidad's trademark: this is a culture that's fearless in the face of creative expression. Its front rooms can be galleries, its backstreet courtyards concert halls, and at its parties, everyone dances.
Do
Play mas
Carnival is for flexing the party muscles, not the eyeballs.
Let rip
"If your parents told you not to do it," says the guidebook, "J'Ouvert is an excellent place to try it."
Drink the rum
When in Trinidad, do as the Trinidadians do.
Don't
Fill your pockets
Bags, wallets, jewellery - all are under threat from Carnival's light-fingered brigade.
Wear white on J'Ouvert
Unless you want to make an invitation of yourself to the mudslingers.
Be prudish
You'll see things in public that would make you blush in your own bedroom.
The practicals
Brian Logan flew to Trinidad with BWIA (www.bwee.com), as a guest of the Trinidad and Tobago tourist board, TIDCO (020 83501009, or www.visittnt.com) Flights to Trinidad cost aboput £450, rising to £750 during carnival season. A single room at the Cascadia Hotel in St Anne's, Port of Spain (001 868 6233511) cotst £58 a night, a double £66. Trinidad Carnival is on March 6 and 7.
