Super Troupers: What's going on? In 1993, a defunct Swedish pop group is back at the heart of British pop culture: best-selling albums, number-one singles, bands paying homage in blue eyeshadow and big boots. Why Abba? And why now?

THEY promise six costume changes in 70 minutes, so for part of the evening I lean against a wall and make a list: white cloaks, silver satin hot-pants, flowing dresses, black raincoats, green and red sequinned loons - and that's just Mike the lighting man. Between costume changes, we get the hits: 'Waterloo', 'Mamma Mia', 'SOS', 'Take A Chance On Me', 'Fernando'. So many hits, so much choreography. 'Fernando' is a highlight, with much swaying and match striking from the audience.

They're called Voulez Vous and they've been together for seven years, but have only tried to be Abba for the past 14 months. The four of them come from Warrington. The two women are sisters. 'They were known as Ritz, and then XTRA,' Lee James, their manager, explains. 'They are a real band, not casted. It just seemed to be a natural thing for them to do.'

James, 41, had been searching for a group to be Abba since 1989. He asked duos whether they would team up with other duos. It was the singer Marti Caine who suggested the two women from XTRA sounded like the two women from Abba. 'I asked them, 'well, how about it?' ' James says. 'They did some demos, and I thought, 'mmm, with a bit of remixing we could really kick it'.'

In March 1992 James flew out to Abba's old recording studio in Stockholm to 'research' the sound. He met Bjorn Ulvaeus, one of Abba's songwriters and keyboard player, who told him: 'We were a highly technical studio band. We spent millions recording.'

Voulez Vous spent only pounds 12,000 in the studio, making backing tapes they use on stage to fill out their live sound. They spent pounds 700 on a star-shaped guitar, just like the one Abba used. They bought wigs and platform boots and paid a designer to measure up the silver satin. They spent a few weeks selecting a name, considered SOS and Waterloo, but plumped for Voulez Vous because it had a certain mystique and sounded a bit European. They played their first big show last November, and went down well.

'It's not a send-up,' James says, 'and because they're not dead it's not a tribute. It's just Abba Nineties-style. The look is as close as you get without plastic surgery.'

Tonight they face a demanding audience. One hundred and fifty prison officers and their partners have gathered in their red-brick social club in Humberside. The club lies on an estate behind Full Sutton, a top security jail that houses terrorists and multiple rapists. 'Someone said we have some of the worst men in Britain in there,' an officer says. 'I said, 'Not Britain, the world'.'

Officers like to let off steam at their club by drinking and smoking and dancing, and Voulez Vous is what they are looking for. 'Top class entertainment,' the club's booker reckons as he watches from the side of the stage. 'I've been here for five years, and we've never had a reaction like this. We've had Mud, Sweet, Bernard Manning. The only band that came close was the Troggs. They're working hard. Good songs and nice girls. Interesting costumes.'

SO IT HAS come to this. In February 1993, with rock'n'roll officially 36 years old, with grunge and jazz-rap and techno at the cutting edge of pop, a Northern showband dresses up as a group from Sweden, a group who were big 19 years ago. And they are getting a lot of work.

Voulez Vous's interest in Abba is not a freak phenomenon. In Germany, a band called Arrival dresses up as Abba. In New Zealand, there is a band called The Dancing Queens. The Australian band Bjorn Again, who talk in cod-Swedish accents even when off-stage, appeared on the front page of the Wall Street Journal: 800 sold-out concerts in their three- year career, grossing about dollars 40,000 a show. At a U2 concert last year in Stockholm, Bono called the Abba songwriters, Benny Andersson and Bjorn, onstage to join them in a version of 'Dancing Queen'; Bono knelt at their feet, chanting 'we're not worthy'. Kurt Cobain, the singer with the Seattle grunge band Nirvana, has claimed Abba as an important teenage inspiration. REM, Prefab Sprout and Elvis Costello have also expressed their admiration. Cover versions of Abba records are hugely popular in gay clubs because, according to Barry Walters, a critic on New York's Village Voice, 'the gals were essentially candy-coated drag queens . . . Abba is to most post-baby boomer gay men what Barbra Streisand was to the previous generation.'

Last year, gay pop duo Erasure recorded camp versions of four favourite Abba songs, and went to number one for several weeks in the summer. In September, Polydor Records released Abba Gold, an album with 19 original hits. This went to number one in Britain, Israel, Italy, Mexico, Portugal, Australia, Denmark, Ireland, German, Singapore, Spain, Austria, Switzerland and Sweden. It has sold almost five million copies. Maybe the Beatles, Elvis or Led Zeppelin you could understand, but Abba?

ABBA FIRST performed under the name Festfolk in a restaurant in Gothenburg in 1970. The two vocalists, Agnetha Faltskog (blonde) and Anni-Frid Lyngstad (brunette), were engaged to the men (Agnetha later married Bjorn, who had the beard, and Frida married Benny, the other one). After several attempts at solo and duet work, the quartet signed to Polar Music in 1972. They toyed with calling the band after their Christian names; they then condensed this to initials only. The record company was owned by Stig Anderson, Sweden's most successful lyricist, with 2,000 songs to his name. Anderson later become their manager, and knew a couple of things about marketing. He knew that to make it big you had to sing in English; and for a Swedish band to make it big they had to sing in English at the Eurovision Song Contest.

Abba entered the song 'Ring Ring' for the Swedish heats in 1973, and were beaten. They won the heat a year later with 'Waterloo', a song that compared a romance with the climax of the Napoleonic wars. It went on to win the contest in Brighton, and the next day they posed on the steps of a beach-hut: 'We are delighted,' they said. 'It's not flash in pan.'

Five hundred million people watched the victory, and although the next two singles sold poorly, their career was made. Nine number one UK singles, nine albums, 240 million records sold worldwide. In Sweden they were only permitted to stay at the top of the singles charts for 10 weeks per record, to give other artists a chance. Most of the songs were about their love for each other; and when they got divorced, many of their songs were about that. The rest of the time they sang about birds flying to freedom, single parent families, and hearts going bing, bang, bong. They didn't take drugs (which is hard to believe these days, looking at their clothes).

They amassed vast fortunes; they became Sweden's second largest export after the Volvo; they bought an oil tanker which sank; they built a recording studio much favoured by Led Zeppelin and members of Genesis. Once it was reported that they had been killed in an aircrash. Bjorn said: 'We had a job persuading people we were alive.'

Abba finally disbanded in the middle of recording an album in 1982, well after their respective divorces (they blamed the pressure and the boredom). They went off to write musicals and to campaign for the rainforest. And then we forgot about them. So what the hell is going on now?

A month ago I wrote to members of the Abba fan club. A week later I received a letter from Farnborough, Hampshire. Ian Jackson, 19, a telesales clerk for an insurance company, has been an Abba fan since he was five.

'No one has ever had the total package of looks, personality and talent,' he writes. 'The image was just right, two guys and two girls, all four with perfect, harmonious vocals. All were relatively good looking, and wore what we remember as being sterotypical fashion of that time. I mean, come on, you can't deny that at some time in your life you wanted to pull on a pair of white satin flares? How about a silk shirt with a big, spangly rabbit on it?'

Abba's newfound popularity irks him a little. He gets mad at the people trying to 'muscle in' on the group because the Seventies are in vogue. 'I am totally possessive about them. Of course, Abba aren't mine, but they have become a huge part of my life - a sort of obsession.'

'They were the glamour of pop in appearance and song,' writes Neil Treacher, 21, from Berkshire. 'No other act achieved this on such a mammoth scale. Not the Beatles or Madonna.'

'Abba managed to be innovative without alienating their audience,' writes Catherine Jelley, a 19-year-old biochemistry student from Coventry. 'They have a song for every mood that you're in. Musically I see them as one of the best bands ever.'

The Abba fan club is called the ABBF - the Agnetha, Benny, Bjorn, Frida fan club, in deference to the fact that they have pursued solo careers since the band's demise. It has its headquarters in the Netherlands, but in Britain is run from a tiny house on the outskirts of Bristol, where Kathryn Courtney, 26, a benefits clerk with Bristol City Council, lives with her parents, brother and sister. She has one quarter of her Abba collection tacked to the wall of the living room and displayed on the sofa. She has posters, official records, bootlegs, scarves and the belts, and then she has the weird stuff: the Abba soap, the Abba silver ingot, the Abba perfume. She explains that the perfume came from Woolworth's in 1978 at a price of pounds 1.99, which was quite dear. There are two types: Frida's, which is spicy, and Agnetha's, which is sweet and flowery. One for night, she says, and one for day.

'I have a wide range of musical tastes, but I always come back to Abba. I play one Abba song a day. It's the tunes, and it's the lyrics as well. They talk about real issues. Take 'The Winner Takes It All' - you can't get any more real than that song.

'Abba were very fashionable in the Seventies. They set trends. Frida was a good example . . . girls would follow every single one of her hair fashions. One minute it would be long hair, then it would be bobbed, then permed. They used to wear leggings and ski-pants in the late Seventies and they caught on fast. Now everyone's wearing them. Then they got into more stylish clothes - evening dresses, and then a lot of people started to wear those. I think we all became that little bit more sophisticated thanks to those two women.'

Courtney doesn't get paid for her devotion. Two other women wanted her job, but she saw them off with her impressive Abba CV. The people at ABBF HQ were knocked out by the fact that in 1986 she set up her own promotion company for Agnetha and Frida. 'I tried to get their solo work heard on radio and television. People in charge just didn't seem to be keen on their solo records, which was unfair. I even wrote to Wogan, and, funnily enough, in 1987 Agnetha appeared on Wogan.'

She loves her work, but the job has some terrible consequences. The other day she received a worrying letter from a fan. 'I won't name him, but I think he has an unhealthy obsession with Abba. I won't be talking to him again.'

'How unhealthy?'

'He sent a personal attack on me. He doesn't like the way I work. He doesn't like it that I talk to the record company, thinks I'm sucking up to the boss, being sycophantic. But I have no boss. He didn't want Abba Gold released because he thought it might fail. He phoned me up two months ago and he told me he wanted to set up a top ten of B-sides. I told him it just wouldn't work, not like that. He got the huff and put the phone down on me.

'Now this guy has typed out a letter and sent it out to 16 other Abba fans. It's a personal attack on me, an attack which he's hoping will damage my reputation. Well he can forget about that] There is no way I'm going to refund his membership. He's paid his pounds 8, he's a member of the fan club and it's tough. I don't want him going around telling everyone 'I've been banned from the Agnetha, Benny, Bjorn, Frida fan club because of my opinions'. He's not going to have that satisfaction. I'm going to be so nice to him it's going to make him sick.'

'KATHRYN is one of the saner ones,' says George McManus. As the man responsible for marketing at Polydor and the success of Abba Gold, McManus gets much flak from the crazies. He's been at Polydor for 25 years. In this time he has learnt the principal aim of record companies is not necessarily to please obsessive fans, or even

the record business; the aim is to delight the mass market.

On his desk in his small Hammersmith office, McManus has a photocopied sheet with the UK sales figures for Abba Gold since its release last September. This sheet is updated every day. Last Monday it read: CD 426,999; cassette 371,037; LP 9,900. Much of this success lies in formatting - you couldn't get so many hits on a single CD or cassette before. PolyGram, Polydor's parent company, bought the world rights to the entire nine-album Abba catalogue two years ago, They sat on it until all previous greatest hits collections were off the market and other licensing deals had expired.

McManus believed a carefully planned new compilation, backed by another advertising campaign (cost: pounds 250,000), could reach a far wider audience: teens bored with Kylie and Jason, clubbers wowed by the Seventies revival and all things kitsch, boomers who had bought the occasional original Abba record and yearned for nostalgia, the middle-aged who recognised a good upbeat tune when they heard it on Radio 2. But there were problems: how to package it to appeal to everyone? And what songs do you include? So he called in a market research company.

Jeanne Trill, 34, an Abba fan, runs a small market research company in Ruislip, Middlesex, and has done work for most of the big record companies. Last May she addressed four groups of people in London and Birmingham. Two groups between 25-34 and two between 35-44. These people were selected in the street, and had to express an enjoyment of Abba to qualify.

The groups were single-sex, 'because if you didn't split them up, you might not get men to admit that they really fancy the women in the band'. As it was, there were discussions on which one they fancied most.

Ms Trill asked them what came into their minds first when they heard the name Abba (satin, platform boots, eyeshadow, classic songs). And what colour they associated with the group (blue - they remembered Agnetha's blue costume on Eurovision, they remembered that the eyeshadow was blue). The listing of their favourite songs influenced the track listing on Abba Gold. And their desire not to see a picture of the band on the album led to the classy black and gold cover that replaced the designer's original (they even chose the colours, believing pastel shades would not reflect the strong beat of the band's music).

Ms Trill produced a 50-page report for Polydor. 'They were very attentive - they always are.'

George McManus believes there is great snobbishness in the music industry. 'It's often embarrassed by its greatest successes. At the time when Abba appeared I heard a lot of people say, 'I really like Abba, but don't tell anyone'. People are coming out of the closet a bit now. Anyway, what the record business likes is irrelevant - what matters is whether I can sell it to the person walking up Hammersmith Broadway. That's all that matters.'

Abba endures, he says, because the best music is timeless: 'It's a personal opinion that's not popular in this building or the music industry in general, but music to me has always meant a melody and a lyric. Popular music over the years has always been like that, but there isn't a huge amount of it around at the moment. There's a lot of dance music and that's become specialised, young people seem to follow one-off records as much as bands.'

Although McManus thought his Abba compilation would do well, he never thought it would do that well. He never thought it would sell so many copies it would delay until next May the release of a follow-up album (which will contain B-sides, and hits not included on the first release).

Few people would have predicted the Abba revival a year ago. But a year ago only a few people were wearing flares, and now you can't move in the clubs for swathes of material flapping at your ankles. A year ago Bjorn Again were only playing at places like Subterania under the Westway flyover in West London, not doing a string of sold-out nights at the Town & Country. A year ago, cover versions of Seventies hits were a rarity; now you can't watch Top of the Pops without them. A year ago, teens may not have heard of Abba; Erasure changed that. It all helped. And there must be something more: a genuine fondness for this stuff, for a time when pop seemed fresher, eyeshadow bluer, and when heels were as high as now. The Abba stuff just came together at the right time. This is what the best pop is about.

EVERY FEW weeks there are rumours that Abba will reform. Bjorn Ulvaeus says he is thrilled with the renewed interest and the unexpected influx of royalties, but denies any plans of a reunion. Bjorn sends his 'good luck' to all Abba tribute bands. He and Benny Andersson are writing songs for other singers, and a new musical to follow Chess, their collaboration with Tim Rice. Benny composed the 'official fanfare' to last year's European football championships; his most recent record was an album of birdsongs. Agnetha has married again, to a Swedish surgeon, and releases the occasional solo record. Frida married a prince and lives in Switzerland, campaigning for green issues.

At the height of Abba's success, Bjorn said: 'Sometimes we joke about what's going to happen when Abba ends. Will we have to shave our heads and wear long beards to start living normally again? To tell you the truth, somehow I don't think we'll ever escape.'

Voulez Vous are on their way home to Merseyside. They have many bookings for the months ahead, including the big one, the Lakeside, Camberley, in June. They may tour the Netherlands, Belgium and Sweden. They recently went to see Bjorn Again perform in Manchester, to compare notes. 'We went in a bit scared, thinking they would be so brilliant,' says Joanne Thompson, one of the singers. 'The boys were good, but the girls were poor. They hardly changed their costumes at all.'

(Photograph omitted)