Pop fans in Korea can be as tribal and fanatical as football supporters in Britain and the atmosphere on their equivalent of Top of the Pops is as partisan as an FA Cup Final. Take the fans of boy dance band Shinhwa, whose 1999 hit “TOP” is a take on Tchaikovsky’s Swan Lake. They wear orange anoraks, are told when Shinhwa are to appear on television and they turn up to cheer and shout when their stars come on. When another band emerges, a different section of fans - wearing another colour - scream and roar.

Although there are two published weekly charts, one issued by the largest local distributor, the other compiled from sales figures of the biggest retailers, teenagers are influenced to buy albums primarily by what they see on television. That means broadcasting weekly pop charts on the two television stations, MBC and SBS, on which producers and the masters of ceremonies or comp res choose the No 1 hit for the week.

In 1992, the first Korean rap artist, Tai-ji Seo, revolutionised these shows by demonstrating that music was for dancing too. It broke the monopoly of ballad singers such as Sun-hee Lee and Yong-pil Cho, who stood in front of microphones accompanied by a studio band. Within a year, Koreans discovered reggae in the hit song “Excuses”. This was publicised through the first Korean music video, filmed in Jamaica. Now teenagers are dance music fanatics - so much so that entreprenurial pop managers are advertising for groups members in the same way that Take That and the Spice Girls were formed.

“The main interest is in dance music,” says Young-min Won, editor of top-selling magazine Global Music Video. “But there’s no variety and, except for the drum machines which everybody uses, the techno of Europe is missing. Songs are mostly about love, rather than topical issues.”

Fin.K.L are one such made-to-measure band, following in the footsteps of the most successful all-boy band, H.O.T (High Five Of Teenagers), who were put together in 1997. Their manager made the boys who had responded to his advertisements audition in front of a crowd of teenage girls and then chose the ones who got the most applause. High Five Of Teenagers, their first album, sold 1.5million copies.

One quirk of the Korean market is that no singles are sold, only albums, hence the need for adjudication in the chart shows rather than relying on singles sales, as in Britain. Nevertheless, albums are popular. Cassettes outsell CDs by a ratio of about three to one in what has become the eleventh largest music market in the world: 46 million Koreans bought 211 million albums in 1997.

As I sit in on SBS’s weekly live charts show, the fans - perhaps 70 per cent middle school and 30 per cent high school students, and 90 per cent female - are ecstatic as dry ice drifts across the stage and the pulse of the drum machine begins. Lit from behind, a coffin raised almost to a standing position is surrounded by boy dancers slowly moving from side to side. Suddenly the coffin lid is thrown off and the close cropped star, Seung-jun Yoo, emerges in a white suit to screams of delight from his fans. This is the hit song from his latest album, which has sold 750,000 copies in two months.

But he loses top spot to all-girl teen band Fin.K.L, whose lead singer is all in white and pigtails. Their dancing was simpler and slower than Yoo’s and their fans younger.

The fashion for white outfits is as pervasive as the television companies’ demands for a clean, innocent image. To achieve this they set dress codes: no navels or tattoos to be shown by any singer or dancer and no earrings or necklaces to be worn by any boy. They allow no sexual innuendo in dancing and no violent or political lyrics. This is backed up with the threat of a media ban that will disastrously affect sales and hit recalcitrant performers in the pocket. Occasionally, notoriety itself is a selling point: D.J.Doc has been blacklisted twice, for taking violent lyrics from American street rap and translating them into Korean.

Out of the television studios the bands are free of such restraints, though their concerts can be much more of a family affair than is the case in Britain. In July, at a concert by dance rap band Clon in the north-eastern city of Chunchon, the audience included a few young children, four American soldiers, some grandparents, some mothers and lots of young teenagers, waving glowing wands from side to side.

This concert, with a host of dancers plus two guest rap groups - Korean concerts never feature just one group, nor is there a warm-up act but rather “guests” - was to promote Clon’s third album. It included loosely disguised covers of “A child is born” and Richard Clayderman’s “Ballade Pour Adeline”, and freely mixed styles of music, including rap, reggae, hip hop and rhythm and blues.

The two singers, Won-rae Kang and Jun-yup Ku, wore jewellery and thin gauze tops; Jun was stripped to the waist to show off his dragon tattoos. At one point, behind a backlit screen, they stripped and changed their clothes. The audience cheered and screamed, but no one surged forward. Those who stood on their chairs to get a better view were politely told off by attendants.

Good, clean, fun-loving enthusiasm seems to be theme in music for all ages, compared to the rough and raunchy styles of our indy and heavy metal bands.

In a Seoul suburb there is an underground scene. It centres on a street of pubs and cafes close to four university campuses where 300 bands perform experimental and heavy metal music. But ballad singers are more popular elsewhere. In one club packed so full it would be considered a fire risk in Britain, I found hundreds of thirtysomethings standing on their seats, screaming for more from Sun-hee Lee. She looked like the girl-next-door who would not have been out of place alongside Dana in the 1970 Eurovision song contest.