'The discos just go da-la-la'

As the bhangra and Bollywood of India's urban middle class drown out rural folk music, a new exhibition beats the tablas for a dying art

You expect ancestor worship to be an exotic thing, and the Sora tribespeople of eastern India don't disappoint. There are the men in red headdresses blowing crescent-shaped horns to summon the dead, the priestess clutching an axe for animal sacrifice. All is as promised by National Geographic. What you aren't prepared for, however, is heathenism's homely side.

The Sora's solemn gesture of reverence, for instance, is to unfurl a sturdy black brolly straight out of 60s Whitehall. While the shamaness enters a trance, children cluster around, still in their school uniforms. And before villagers dance with the spirits of long-gone relatives, they change into their best outfits.

The other revelation is the music. To wake the dead, the Sora assemble a peasant orchestra of oboes and drums. It is scratchy and raucous and fervent - surely, you think, an ancestor deserves something more stately? But no, this is the soundtrack - and the entire ritual has been caught on film for Utsavam, a new exhibition at London's Horniman Museum, of music from across India. Utsavam is full of such rarities - and goes some way to showing just how varied the country's culture really is.

Indian music in the UK is dominated by Bollywood and bhangra. Both are popular in India, but they aren't all the subcontinent has to offer. Those cliches about a billion people speaking dozens of languages and even more dialects are just as true of India's music: it has not one style of classical music but two distinct ones divided roughly by geography, and dozens of forms of folk music varying across regions. The Horniman showcases five provinces, stretching from the eastern Himalayas down to Kerala in the south-west; Utsavam's curators regret not being able to squeeze in more pit stops. "Each region is very different," explains Rolf Killius, who did most of the legwork for the exhibition. For example, rhythm becomes more important the further south one goes. "Even southern classical music is much more percussion-based," he says. "The melody is sometimes there just to support the rhythm."

Kerala's temple drumming is a good example. It's a big industry in the southern state - Killius cites one district in central Kerala with 60,000 residents, of whom 2,000 are professional temple musicians. Large festivals attract thousands of Hindu worshippers, convoys of elephants carrying shrines, and orchestras of up to 200 instruments, mainly drums. A single piece can take up to four hours, and is improvised from a rhythm known both to musicians and devotees - and one that gets ever faster. "By the end, the pilgrims are swaying ecstatically, and the drums are going, 'Brrrrrrrrrr ... '"

Such complex music has much in common with India's classical tradition, says Somjit Dasgupta, who plays the classical sarod, a stringed instrument held like a guitar. "I was taught folk - and that these divisions were made by scholars for easier classification." Even Indian film music used to feed off both classical and folk. "Up until the 50s, you had great composers who were influenced by all these types of music. Now the film industry doesn't want to know - and the discos only play noisy tunes that go, 'Da-la-la.'"

Or something like that. Music-lovers aside, peasant culture has long struggled to get respect outside villages. A classic Indian film from 1969, Days and Nights in the Forest, adroitly captures the traditional urban condescension towards country life. Directed by the legendary Satyajit Ray, it shows a group of Calcutta professionals on safari in search of aborigines similar to the Sora. When they meet the villagers, the result is mutual incomprehension. The city gents wander off to get drunk, ending up in the middle of a dark forest doing a dance they name the Tribal Twist.

The divide has only been widened by India's famous economic boom. The burgeoning middle class is definably urban; British notions of downshifting to arable isolation, with only a broadband connection for company, are yet to catch on. At the same time, the rural outlook is increasingly bleak. Agriculture - which still employs about half of all Indian workers - is in dire straits; every half hour a farmer in India commits suicide. Against that background, who wants to play or hear tales of rural life?

"Villagers nowadays feel increasingly ashamed of their culture and their simple instruments," says Killius. "And with television reaching the countryside, there's no need for farmers to do a performance of their own. They can see Bollywood song-and-dance routines more elaborate than any village recital. It's especially sad when you walk into a tiny village: someone brings out a little fiddle - and they play only filmi music."

When villagers emigrate to towns for work they often leave behind their musical traditions. The Jew's harp was once a staple instrument for the Monpa communities that border Tibet, but now it is nearly extinct - its low throb simply can't compete with urban noise.

Even bhangra, the one strain of Indian folk to thrive, has changed almost beyond recognition. It used to be a farmers' dance confined to the north-west region of the Punjab. Today it has migrated to city nightclubs - and is louder, coarser and more showbiz than any Punjabi farmer of the 50s would credit.

As the range of folk music narrows in India, so does what we get in the UK. "Every mela [community festival] here says it's showcasing Asian culture, but only plays bhangra and Bollywood," says Viram Jasani, a promoter of Indian music for over 30 years. "Other music of real beauty and history - both classical and folk - just gets lost. And because they never get to hear about the other stuff, UK venue owners assume it has no audience, and don't put it on."

So musicians can't find a marketplace, and audiences rarely hear new musicians. Since Indian music is not written down but passed on orally, an entire fragile tradition is under threat. "Folk is still there, but it won't be in 20 years," Killius predicts.

Such gloom is justified in some cases, but not all, suggests Dasgupta: "Even now, I come across beautiful folksingers in Bengal, housewives in the Punjab who sing traditional melodies ... There is still genuine folk music that people share and enjoy."

An example of that is in one of the Horniman's films. It shows the Keralan temple drummer Kuttan Marar teaching his children to play the centa drum, a heavy, shoulder-slung instrument. They sit on a bamboo mat outdoors with the girls behind, since only boys are allowed to learn. Every time the youngest throws up his drumsticks, his sisters rear back to duck a black eye. The boy looks about five, and pretty useless on the drums. But he seems to be having a high old time.

· Utsavam is at the Horniman Museum, London SE23, until November 2. There is a special Sitar Day on Sunday