Why it's castanets at dawn for Spain's flamenco performers

The swirling hips, the machine-gun rat-a-tat-tat of the dancers' feet, the agonised imploring of a singer seeking to transport the audience to that elusive state of mind known as duende; flamenco is pure passion, nothing less.

But in this turbulent world, in which cantaores (singers) regale audiences with tales of scorned lovers and tragic deaths, the emotions off-stage can prove just as heated, if not more.

Though flamenco is a relatively "young" art, which people only started to pay to see about 160 years ago, arguments about the "purity" of the form are endless and typically stormy. On one side are the fundamentalists, or puris-tas, who admit no diversion from the path of what they see as the true faith. For them, those who mix flamenco with other forms, such as classical ballet, contemporary dance, jazz, or even pop, have diluted the art into a pastiche of the original only worthy of the tablaos, or tourist shows.

On the other side are the innovators, who are constantly mixing - or, as they see it, enriching - this very Spanish art form with other different types of dance, music or singing in order to push back the boundaries. And even among those pioneers, rows blow up if one claims credit for an innovation that was the work of another maestro.

So, when the dancer Joaquin Cortes, one of a small band of modern-day galacticos, or stars, nonchalantly declared that it was he who had revolutionised the way flamenco is danced, hackles were immediately raised.

Cortes, a roguishly handsome man who stirs the hearts of female fans without moving a muscle, is an accomplished performer in his own right who has added much to the form. But it seems that he had forgotten to pay a debt of respect to the late dancer Antonio Gades, one of flamenco's most famous innovators. Cortes swiftly paid the price: the crowds were less keen to flock to his next shows in Seville, perhaps the capital of the flamenco world.

Gades was the first flamenco dancer to perform at La Scala, Milan, the shrine to Italian opera, and formed his own company with his dance partner Cristina Hoyos in Paris in 1969. Gades and Hoyos turned flamenco upside down by using techniques found in ballet and other dance forms, but without diluting flamenco itself. He hated the way folk tales had been trivialised in the form of flamenco that prevailed at the end of Franco's dictatorship. Instead, he took them seriously and made them what he called "stories with movement".

Gades and Hoyos themselves were accused by the purists of harming the essence of pure flamenco by mixing it with other dance forms. But in a rare interview, Hoyos told The Independent: "We did not mix the form. We enriched it. Like other forms of art, if flamenco does not evolve it becomes boring. There are those who want it to stay the same, the purists, but you should want to advance not stay where you are."

Hoyos, now director of the Flamenco Ballet of Andalucia, added: " Flamenco is such a strong art form that you cannot dilute it if you introduce new things, only help it to grow. You should be opening new doors."

But others, like the flamenco singer José de la Tomasa, passionately disagree. De la Tomasa, who belongs to a more conservative school of flamenco, says: "I have nothing against mixing the form but it can result in a loss of quality. When you take things from other styles, this can happen to the original flamenco."

Worse than those who want to try out new forms are the likes of Cortes, and other dancers such as Antonio Canales, Sara Baras, Eva Yerbabuena, whose worldwide fame has made them as popular in Britain or Japan as in their native Spain. The romantic appeal of flamenco and its highly photogenic stars have made it attractive to advertisers, and some have even become pop stars in Spain, with all the trappings of such fame. But for the likes of De la Tomasa, this is part of the problem: "There are no good or bad flamenco singers or dancers now. But there is a lot of marketing. Perhaps Cortes dances well in private, but for the public he changes. Some performers now are all marketing."

Two flamenco legends, the guitarist Paco de Lucia and the late singer El Camaron de la Isla (literally The Shrimp of the Island) both met with fierce criticism when they first started to experiment with different forms in flamenco during the 1970s. When El Camaron first introduced an electric bass into the sound, it was rather like the moment Bob Dylan went electric and was booed at the Newport Folk Festival in 1965.

El Camaron was undaunted by the criticism and went on to develop what is known as Nuevo Flamenco. When he died in 1992, his funeral was attended by 100,000 "worshippers", and he is still regarded as a flamenco deity. Paco de Lucia, for his part, broadened the scope of the art, crossing into the worlds of classical, jazz and "world" music.

Both of the seflamenco artists are, of course, now revered, even by those who first criticised them. But it is flamenco dancers who pose the biggest threat to the old guard as dancing allows more freedom to incorporate different styles than singing or playing the guitar.

Yerbabuena is among a generation of dancers, including Israel Galvan, Mario Mayan, Manuela Carrasco and Andres Martin, who are seen by traditionalists as arrivistes. José Maria Segovia, who heads the Seville flamenco-club federation, says: "We can't forget where we came from. Flamenco has to be flamenco. You must be able to tell when you're listening to a solea."

Other bigger changes are taking over flamenco, leaving its origins as a form of folk singing popular among Gypsies long behind.

In recent years, a fusion between pop and flamenco has emerged called " flamenco chill". Bands such as Chambao, which added African music, and Ojos de Brujo are its best-known exponents.

Even where flamenco is performed has changed. It used to be found in peñas, or intimate dances with a few friends gathered round.

But with its growing popularity, stars such as Cortes can only to be seen at sold-out performances in large theatres or arenas.

The genre has become particularly popular in Japan, even spawning a new generation of Japanese dancers and singers, who try to find the duende, that mythical state which all flamenco followers look for. Japanese housewives leave their salarymen husbands at home to study flamenco in Spain for up to six months. For the top flamenco performers, touring Japan is a must as the Japanese are the biggest flamenco fans in the world after Spaniards.

But Professor Rafael Infante, an adviser to the Seville Flamenco Biennial festival, believes that the roots of the art are being forgotten in pursuit of financial gain. "In Andalusia we don't give flamenco the importance it deserves, not just as a first-rate cultural asset but as a potential source of revenue. But I don't think we should let ourselves be guided by purely monetary considerations."

To some, though, the row over the purity of flamenco seems ironic as it was an art form which only really emerged in the 19th century and has a mixed, multicultural heritage. Tina Panadero, director of the Flamenco Museum in Seville and an expert on the genre, says: "What people don't realise is that there is no definition of flamenco. It has only been around for about 150 years, and is always changing. Each family will have its own style of performing flamenco, so there is no one type of flamenco. It is constantly changing, as I think it should."

From the First World War onwards, shows were put on all over the world. But flamenco was not appreciated by all - some believing even then that its very popularity was killing the soul of flamenco. The Spanish composer Manuel de Falla and other intellectuals even organised a contest to find the authentic cante jondo (flamenco singing).

Originally the property of Gypsies, flamenco is said to have Indian, Arabic, Latin American and Cuban roots. The first flamenco schools appeared around 1760 in southern Spain, but it enjoyed a golden age between 1869-1910 when it became established in café cantantes (music cafés). Dancers were the main attraction but soon guitarists won over the audience, too.

From around the 1950s, flamenco hit the big time, with performances in major theatres and dancers, and guitarists especially, refining their style.

Back at the Flamenco Ballet of Andalucia, the top dancers of tomorrow practice a zapateado, the bewitching 100mph stomping that is a feature of every flamenco performance. But just as this fiery art form has done before, one wonders whether these dancers' future moves will provoke the ire of a new generation of puristas.