Theyam, Kerala and the Barbican

4 am. Eternal. I'm at an all-night temple festival somewhere in north Kerala in southern India - not so much in the middle of nowhere as on the outskirts of nowhere. There's wild chenda drumming and a terrifying apparition of a man who has gone into a trance – the goddess Babrakali, they tell me, has possessed him. He's wearing an outrageous red costume 12ft high, and he is charging right at me. The fact that his outfit is on fire, that he's just bitten the head off a live cockerel and the remains of the unlucky fowl dangle from his mouth, doesn't reassure me.

In fact, he stops just in front of me and shoves a few bird feathers into my camera's flash unit. "It's a good sign," says the guy standing next to me, "your camera is now blessed."

I'd arrived in India at Chennai the week before.There were still some signs calling it Madras at the airport. On one of them the R was missing which thus read "Mad as India". The perfect welcome. The nearest town to the Theyam, the ritual dancers I wanted to meet, was Cannanore in North Kerala, where I'd arrived to find the whole place on strike. There was no transport and I wandered through the streets with my bags looking for a place to stay.

Southern Kerala is already a hot tourist destination, particularly around Trivandrum (which is now officially Thiruvananthapuram, perhaps to deter visitors). But for the moment Cannanore is so far off the tourist trail that two Austrians accosted me because they were curious to see another Westerner there. Their excuse was that while poring over a map some ash from their cigarette had dropped in a mystic sort of way on Cannanore. Fate had directed them to see the Theyam.

As we talked, a figure appeared on a motorbike, asked me my name and instructed me to jump on the back ("Wow, just like a movie" said one of the Austrians). And I was whisked off to see the mysterious Dr Nambiar, who has made the study of the Theyam his life's work. Later, someone swore he had seen Dr Nambiah in Trichur at exactly the time I met him. But then, I had noted a curious passage in Autobiography Of A Yogi by Paramahansa Yogananda on the plane out that one of the signs of a realised master was the ability to manifest in two places at once.

I arrived at Nambiar's rural hideaway, where he talked about the Theyam over a cup of the strong milky coffee they go for in south India. He told me that partly because the South wasn't so affected by the series of invasions that convulsed the North, many south Indian cultural forms go back relatively unchanged for centuries. Elements of the Theyam ritual can be traced back to neolithic times, although the modern (modern as in about the 14th century) version is a synthesis between the indigenous Dravidian and Brahminical culture.

It takes about 10 years to train as a Theyam performer and each of them will know hundreds of songs. Preparing for the ritual is intense. Each performer will fast for days and the make-up takes about four hours to apply. The costumes, bulked up by layers of flame-coloured fabric and shiny metals, can weigh 60 pounds and can measure up to 15 feet high and several feet wide.

After the introductory songs by a kind of MC called the Tottam, several hours into the ceremony the Theyam dancer goes into trance, the Goddess descends, and at this point the performer as deity is deemed to have supernatural powers. The Theyam works as a kind of oracle and the village elders ask questions about everything from the rice harvest to village disputes. While in trance, the Theyam is also is believed to have healing powers - In the old days these were said to be particularly effective against smallpox.

I heard numerous stories such as scars disappearing during a Theyam performance. But as Dr Nambiar put it, "the mind is enormously powerful, and if someone believes strongly enough, all kinds of things are possible." A formerly sceptical Madras woman I met  told me that the Theyam had told her it was her birthday, which it was although she hadn't told anyone, and became convinced of the Theyam's magical powers. Certainly the atmosphere in these rituals is charged, and Nambiar believes that the performers reach some kind of highly developed intuitive, even psychic state.

Of course, the endless drumming, the flickering fire, and the flash of the costumes tend to induce a meditative state - with the performers occasionally charging at you keep you awake. A little like Zen masters who have a habit of bashing their pupils over the head with sticks during meditation sessions. Although the Theyam is an ancient form, I was reminded of various avant-garde theatre groups, such as the Catalonian Fura Dels Baus who have a habit of throwing flour or water at their audience which certainly keeps them alert.

The chenda drummers which provide the musical accompaniment to Theyam and the better-known Keralan dance of Kathakali is an ancient art form itself. The two-headed chenda drums are made from the hardwood of the jackfruit tree. Drummers form ensemble of ten or more to perform what they call Theyambaka.

The way they learn is to vocalise the rhythms and then play them with very heavy sticks to promote muscle development. Each rhythm is doubled and trebled in speed until the quadrupled speed in the hands of an expert is "hard to hear, let alone play", as one Indian music pundit put it. The combined rhythm of 10 or more of these drummers is like drowning in a complex mathematical soup of noise.

A Theyambaka drummer I met in Kerala explained that he started learning at the age of four by getting up at three in the morning and practising three hours a day. Probably not as bad as the film arranger I also met who was actually chained by his father to the music room.

After a night of Theyam I got an all-night train south to Varkala, feeling extremely disorientated with the rhythms in my head compounded by the antique train shuffle and the food vendors' repetitive chants of "caffecaffecaffecaffe" or "cutletcutletcutlet".

The encounter with the Theyam was like a waking dream, a powerful and memorable experience - so when I heard that the Barbican had arranged for a couple to fly over with some chenda drummers for their Transcender Weekend just gone, I was fascinated to see them again.

But when they came on stage they seemed reduced in size and stature, to the point of banality - the fire ritual element and the animal sacrifice elements had, of course, been cut out to reflect European sensibilities and the health and safety regulators.  While the costumes were impressive as ever, they flailed about looking a bit lost for 20 minutes accompanied by three drummers and the audience respectfully applauded.

Admittedly, I'd been privileged to see them in situ, but the question of whether such ancient religious rituals can or should be transferred half-way round the world and put in a theatre is a valid one. A simpler question is whether such rituals work as spectacle when exported - this one didn't. Others fare better.

An evening of Sudanese Voodoo music takes place at LSO St Lukes on Wednesday. Book here.