For a self-confessed obsessive music manager, smiley, friendly Louis Walsh appears very normal, almost disappointingly so. Managers, particularly those managing pop stars, boxers and football teams, tend not to be overly popular and are probably as disliked as bank managers. But while the bank manager is a grey man in a suit, managers of music bands have an aura of intimidatingly "cool" power. Some of them possess a vaguely messianic demeanour. Ireland's most high-profile band manager, Paul McGuinness, increasingly resembles Orson Welles and has developed the gravitas - as well as the bulk - of a judge.

But Walsh, the will o' the wisp creator of Boyzone, appears, at least outwardly, to be untroubled, seems to be having a good time, and can always count on being able to get lost in a crowd. Does he see himself as McGuinness's rival? "Not at all. He's really the fifth member of U2. I admire him but I don't want to be him. He's Mr Rock and I'm Mr Pop. Anyhow, I hope to keep my hair and I haven't put on any weight."

There is no glamorous Girl Friday at Walsh's side. He is not wearing a black satin suit. He does not have earrings, nor is "darling" his standard form of address. Apart from the fact that his mobile phone appears to have become part of his body, Walsh, who breaks into song at the mention of a title, could be involved in anything from selling cars, or fixing them, to running a stable or his own electrical shop. But the only business he has ever known has been that of popular music. "It's all I've ever been interested in, since I was a kid. There was nothing else. Football? I hated it."

His responses are clear cut, free enough of jargon for non-pop-industry people to understand him. Walsh tends to either love something or "hate it, hate it, hate it". The small-town life he knew as a boy in Kiltimagh, Co Mayo was never for him. His father had had a farm in the town.

"I never had any interest in farming. I'm glad I grew up there; it hardened me. It made me determined to get out and do something." His remarks are not as harsh as they might read in print. Walsh is a mild-mannered, pleasant man, a bit of a Peter Pan, used to saying what he thinks and intent on a crusade - that of securing the future of pop music.

"Pop has never been bigger," he says, and makes the distinction between it and rock. "Rock is much more serious. And I think the problem with rock stars is that they are always having to be doing something else. They are also very taken up with justifying themselves. They want credibility." What he says begins to make sense. After all rock stars such as Sting and Bono have long since been preoccupied with saving the world. "Pop stars are entertainers. We [Boyzone] have no message; we are entertainers. The lads are out there to sing to the kids. There's nothing more to it."

Walsh is not trying to influence mankind; he merely wants to have a say in the music bought by the discerning 16 to 25-year-old age group. The success of Boyzone is difficult to ignore, if equally difficult to understand. Their particular brand of soft pop, complete with choreographed presentation which has to date earned them 15 Top 5 five singles, six No 1 singles and three No 1 albums, seems to the uninitiated to be remarkably forgettable.

Having listened to their new album, Boyzone By Request, which includes their cover of the Cat Stevens standard, Father and Son, there is not that much to say about them. None of them plays an instrument, "they are strictly vocalists". But pop does tend to infiltrate and stick around that bit longer than more strident rock songs. Walsh believes in his band but he is not defensive: if he suspects he is speaking to a non-fan he neither attacks nor attempts an on-the-spot conversion. More than most he appears to abide by a live-and-let-live policy.

The phenomenon of the boy band is also that bit harder to take seriously beyond that of the barber shop quartet - not that Walsh's band could be confused with a barber shop quartet. The phrase "boy band" itself doesn't help. It evokes the image of Teletubbies dressed in sailor suits prancing about in heavily synchronised dance routines.

Boyzone, it must be said, are a lot less menacing than the Spice Girls - not that they are exactly choir boys either, and look tough enough to appear slightly silly in some of their dreamier routines. Of the Spice Girls he says: "They have definitely peaked. They won the Lotto. I admire what they've done - great marketing and great fun for a short time - but overall the image is tacky. Let's see how they're going to do as solo acts."

Yet while Louis's boys have survived for six years in a market with a shelf life, according to him, of "about three to five years", many imitators have failed. "It's a tough business; there are a lot of bitter also-rans. It's also about more than music or whether you can sing or not. It is a complete package - looks are terribly important. Stylists play a huge part in the making of any band." And the boys are no longer boys.

The famous five - Ronan Keating, Stephen Gately, Shane Lynch, Keith Duffy and Mikey Graham - are now men. Four of them are married, they have children, while the fifth, Gately, recently went public in the Sun on his homosexuality.

It is not necessary, however, to ask Walsh about this. He introduces the subject himself. And no, it was not a carefully orchestrated publicity stunt, he says. Gately's announcement was forced, he maintains, by the Sun saying it was going to "out him". "I was very worried about the effect it would have on the fans. The girls love Stephen; he and Ronan get the most fan mail between them. But it has turned out far more positive than I imagined. I think he will become a kind of gay icon. Irish kids will have someone else to look up to aside from David Norris. They will be able to identify with Stephen and he's a great guy."

Walsh is hyperactive and therein lies the secret of his success. Is he a millionaire? "No, I'm not as rich as people think. For a long time I was involved in this business and I made nothing. It's very hard trying to get your money for gigs in Ireland. There's an awful lot of crap. I mean, Jesus" . . . for a moment, the memory of his previous struggles causes a world-weary expression to race across his face . . . "when I formed Boyzone in the late winter of 1993, we went on the road, touring the country in a white van, and it was a nightmare trying to get paid." He gestures at the horror of it, before returning to his cheerful self, sitting forward, rocking slightly, looking up as people pass by his chair.

The mobile phone is off again, and someone on the other end is being told that Boyzone are in Germany - "they're big in Germany" - and will be appearing in a charity concert with Michael Jackson. Then it's Amsterdam, and Walsh will be there.

Even if the small black bag with the Aer Lingus Gold Circle Club tag was not on the floor by his side, Walsh would still give the impression of being forever on the move. He has no children, he is not married, there are no pets. "I'm just into the music." He is restless, even jumpy, but in a likeable way, and sounds more like a fan than a Svengali. Being a manager is not just about the money to be made, and his cut of 15 to 20 per cent is modest by the standards of boxing and snooker managers. "You have to keep the product in the public eye. That means talking to the press, making sure the radio stations provide the air time. You are constantly pushing, you have to. It's very competitive."

One of nine children, seven boys and two girls, Walsh was born in July 1956. He was the second child, "but the first son". He claims he was hopeless at school and was only interested in listening to Radio Luxembourg. His mother was anxious to help him and sent him off to boarding school in Ballaghaderreen, Co Roscommon. It was a disaster. "I hated it, the food was awful. It was like a prison."

Back home in Kiltimagh, he completed his Leaving and in time-honoured fashion practically ran all the way to Dublin, where he slept on his eldest sister's floor. At 17 he went to work with Tommy Hayden - "you won't know him, but he was huge in the show band era. I learnt my job from him." It sounds hard graft.

The years of his apprenticeship in the music business ran parallel with the peak of the Eurovision Song Contest, long before it became a running gag about political voting. Two of Walsh's singers, Johnny Logan and Linda Martin, won it (Logan twice). Walsh makes no secret of the fact that he was once the contest's most ardent admirer. "But not now. It's really gone downhill. But when it was at its best, people took it seriously. Countries sent their best singers, big names like Sandy Shaw. They wanted to win it. Now they're all amateurs; it's a mess."

Of this year's winner, he says "yeah, it's a goodish pop song but who'll remember it?" That Swedish win brings the conversation around to that country's previous winner of some 25 years ago - enter ABBA. In common with so many serious chroniclers of pop music, Walsh praises the group it was once fashionable to laugh at. "ABBA were, are, fantastic. Great songs. Their songs will live forever. Their album is still No 2. They were before their time. No one realised just how good they were."

Soul music is Walsh's first love, and he quickly fires off a list of singers. One is Marvin Gaye. Mention of Dusty Springfield achieves the expected reaction from him. "I love her. She is the greatest. You know she was half-Irish: Mary O'Brien? Great, great singer. The best black voice there was," reeling off a list of her hits: You Don't Have to Say You Love Me, Goin' Back, Son of a Preacher Man, Just Don't Know What to Do With Myself, Wishin' and Hopin' . . . He sings the first few lines of each and also praises The Pet Shop Boys as being clever, ultra-professional and original.

Part of Walsh's weekly ritual is chart-watching. "Every Sunday morning at five past seven, I'm up and tuned into the BBC Teletext." What does he do aside from breathe music? "I'm out and about. Restaurants, friends. I live in Dublin. I have a place in Clyde Road now. I love Dublin."

How about the future for Boyzone? Now that Ronan Keating has launched a solo single, does that mean the band is breaking up?

"No, they are as popular as ever, and they are good friends. They can fill the RDS any time they want. They all have individual projects, but Boyzone will continue as a sort of safety net for them."

Walsh is determined they will finally crack the US market. He agrees they have failed in America while the Spice Girls have done well. "Boyzone are huge in Europe and Asia and of course in Ireland and the UK." His other band, Westlife, another boy group - three of them are from the west of Ireland, the other two are from Dublin - are also doing well. "They're in Germany with Boyzone."

But is it not difficult having to relate to teenagers and twenty-somethings when you're 43? He laughs: "No, the age thing doesn't matter; it's the music." How about his stars' parents? Are they not afraid of their sons becoming involved in a traditionally drugs-and-drink-and-sex world? The parents seem more pleased than apprehensive of the money involved. As for the drugs etc, Walsh stresses he is very strict. "The boys have always known, `do drugs and you're out'. I think they are well behaved. I mean there's been babies before marriage, but no scandals." Pop singers, it seems, are not as troubled as rock stars. Recently, Walsh held auditions for a new band with a boy/girl line-up. About 1,000 hopefuls turned up at Dublin's Red Box. Walsh admits he was not overwhelmed by the talent on offer. But he has not given up hope.

Planning to repeat the Boyzone formula by recruiting a number of individuals and forming a band seems so much more cynical than a band emerging from a group of young fellows getting together in a garage and trying to make it big. The observation returns Walsh to his earlier comment about the packaging of a group as a product and the importance placed on looks. His stance is simply that he is supplying a commodity for which the demand is limitless.

Among Walsh's other projects is his bid to buy a radio licence, for which he has joined up with John Reynolds of The Pod, fashion designer John Rocca - "he's very interested in music" - and U2's The Edge, with the support of the largest independent radio group in Britain, EMAP. In EMAP, Walsh and his colleagues are dealing with a Dubliner, Paul Kavanagh: "And he knows there is a market here - there's a huge market out there of 16 to 25-year-olds and I don't believe they are being properly catered for at all." If successful, would Walsh be interested in becoming a DJ? The informed patter would be no problem, as talking about pop music comes so naturally to him. "No, I don't want to be on the radio" - he simply wants to own it.

Aware that Boyzone reinvented pop music in Ireland, he is quick to point out, "the biggest story in Irish music is Enya. Now she is unique. There she is, holed up in her castle, no family, doesn't have to see anybody, doesn't have to do live gigs and has massive sales." Agreeing that it would be difficult for her to produce her sound live, he says: "I think she is the one. I also love Van, he's just great, amazing." Mention of Sinead O'Connor makes Walsh react at his bluntest: "Sinead, well I think she needs controversy and she doesn't sell half as many albums as Enya. Enya sells 40 million and she doesn't say a word."

Meanwhile, every record company is pursuing Walsh for a contract with another of his singers, Samantha Mumba, a Dublin girl of mixed race whose pop soul big voice is attracting attention. "She is only 16, and it is obvious she has a big career. For a change everyone is phoning me about her instead of me calling them."

Although he has become a power broker, Walsh remains the music-obsessed kid. It's a bit like living in an extended childhood. He laughs at this and says: "I know. I'm not complaining. I love music and I love the scene. I'm happy." But, always on the sidelines, did he never have dreams about being a performer? "Never. Anyhow I don't have the looks. No stylist is that good."