All the record-buyers who will flock to purchase his latest album, Unfinished Revolution, may not support every cause Christy Moore propounds but they long ago licensed him to speak on issues others remain mute about. So when Unfinished Revolution was released last week the occasion was a real cultural event on a par with, say, the latest Neil Jordan film or Seamus Heaney collection.

He's gradually accumulated his influence over the twenty years since a young Kildare bank clerk dumped his job and bunked off to Britain to try his fortune on the then-prospering UK club circuit. Through his career alone, the evolution of Irish folk music can be traced.

In 1966, Ireland was truly another country, this real Ireland both stranger and more distant from us than any Summer of Love the media might now be celebrating. With a national dedication since departed, we commemorated the 50th Anniversary of an Easter Rising whose values and personalities were still palpable.

Eamonn de Valera, Sean Lemass and Frank Aiken still reigned, Oliver J Flanagan was a mainstream politician, Archbishop McQuaid still thought Trinity College a nest of dangerous heretics, Ian Paisley was a marginal cleric in the still slumbering North, sex was something Unionists bagged coal in, the only acid drops were Lemon's sweets and Ireland's disc jockey was Leo Maguire of the Walton's programme, imploring his listeners: "If you feel like singing, do sing an Irish song" - which invariably seemed to be Sean O Se's 'An Phuc Ar Bhuile'!

But in 1966, the musical revolution was being plotted in O'Donoghue's where Sweeney's Men strove to integrate the split hemispheres of a sensibility that accepted both Bob Dylan and Irish traditional music. Moore was close to that set. In 1970, he returned to Kildare to record Prosperous, a solo album that sparked the formation of Planxty, the first and most significant of the Seventies collectives, as they forged a new course between ballad bombast and traditional purism. In his own Polydor solo albums of the mid-Seventies, Christy Moore also mildly experimented, frequently including electric instruments.

Outwardly, his career was going well. Both solo and with Planxty, Christy Moore was nurturing his formidable and versatile range of talents, even then an intimate interpreter who could hush an audience with a ballad and then enliven it with the sharp touch to undercut a luckless heckler.

But though Planxty could fill the National Stadium and reap their rewards at summer European festivals, they never broke through to the coveted American and British rock markets. There were other personal dissatisfactions at the time also, for drink wasn't helping Christy's discipline.

Then he met his Damascus at Carnsore Point. With Des O'Malley as salesman, Jack Lynch's last Fianna Fáil administration planned a nuclear reactor on the Wexford coast. Their opponents organised a protest festival on the threatened Carnsore site which Moore and his closest musical associate Donal Lunny duly played. They departed, conscience-struck by the irrelevance of their music - allegedly people's music - to their own society. Soon after, Christy appeared on the Late Late Show singing an anti-nuclear song that immediately prompted a riled and complaining phone-call to RTE from Lynch's wife, Mairin. The campaigner Christy Moore had arrived. He's got up many nostrils since.

But, to be precise, this conversion wasn't an absolute reversal of his previous stance. Moore was among the few Seventies folkies - Luke Kelly and the Dubliners were another notable exception - who included Woody Guthrie and Ewan McColl songs in his repertoire. He wasn't infected by the syndrome, very prevalent in Britain, of nostalgically concentrating on Child Ballads from medieval history's beyond and forgetting folk music's contribution to the struggles of the Thirties depression. But not long after Carnsore came Moving Hearts. Christy Moore's politics became codified and committed as never before.

Moving Hearts were the most ambitious and provocative group ever to emerge from the folk milieu. Live they could be awesome - at peak form, the only other essential Southern Eighties experience besides U2 - but in the studio, they never consistently did themselves justice or quite drew together all their threads of influence.

Their politics also stepped in where others feared to tread, Moving Hearts drew a line during the Maze Hunger Strike, supporting the prisoners, a policy which made them the first Irish act of any repute, to identify with any aspect of the Sinn Féin cause, breaking with the established rock and folk consensus not to take sides on the Northern issues. And since Christy Moore left Moving Hearts he has made no apologies for his views, even including songs by the late Bobby Sands on his Ride On album.

Since his departure from the Hearts, Christy has embarked on the most significant phase of his career. Now drawing on all his professional experience and skill, Moore finally got overdue support from a record company, WEA to release a chain of indispensable albums. And though he initially faced obstacles in international promotion and distribution, British, American and Australian tours have enlarged his reputation abroad.

Perhaps the man has found his time. The emergence of acts like The Pogues and Billy Bragg has suddenly given him a new context and a younger audience who've realised folk music need not be confined to antiquarian history lessons and who may now see Christy Moore as an exemplar and father-figure. Christy Moore may not yet sell truckloads of boxed-sets - but he is one Irish artist who might just in time be accounted a major influence on the international music of the late Eighties and Nineties.

We meet under a sign of truce. Ever since a rancorous Moving Hearts interview long ago, our relationship has been wary due to our different views about the North. We could re-enter the lists again but I doubt if it would be profitable, particularly since Christy's views have been ventilated in so many interviews since. Besides I want to discuss his music.

Few recent Moore articles have concentrated on music or indeed on his own sense of what makes him tick as a performer. The British experience of dodgy agitpop bands has proven that acceptable radical rhetoric can often be abused to disguise a multitude of artistic faults. Christy Moore can never be accused of those sins.

But might he be lured by crossover dreams? Musically, Unfinished Revolution is gentle and soothing, an album that reminds the listener that Christy Moore is also a member of the Laidback not the Laibach Generation. More a soft-rock album, Unfinished Revolution is also almost completely bereft of Irish traditional instruments. But Christy Moore is quick to spot any insinuations that the album was specifically designed to cosset any fainthearts in WEA's international departments.

"I was actually considering this album immediately after I finished Ordinary Man, as I'm now considering the next one," he reflects. "I felt after Ordinary Man that it was time to make a drastic move, that I didn't want to continue in that vein. Which isn't to say I wouldn't go back to it in a few years time. But I wanted to excite myself by doing something radically different.

"My priority is for my albums to be released in Ireland," he adds, "I record my albums for the Irish audience so if you're saying did I purposely aim this album at a wider audience, the answer is definitely No."

He goes even further: "If there is a possibility of the album being released in the States, I think I would remove three tracks from it - but that's more because I'm not happy with the tracks and I would have time to change."

He also reminds me that the issue of traditional instruments can be over-stressed for, in his own way, Christy Moore is a guitar man: "There's no accordion or pipes on Ride On, or on three of the last four albums. In fact, the last album was the first time out of 21 albums that I ever used accordion on two tracks - so I wouldn't get too bogged down in that. Actually I did try pipes on three tracks but it didn't happen. But I'm not severing any connections with traditional music."

The crossover angle can also be dispensed with because though London WEA are finally releasing Unfinished Revolution, their American cousins remain apathetic: "There's still absolutely no recording company interest there. There's an audience for me which is half Irish, half American, which is increasing all the time. But I think I've gone as far as I can go in America without recording company involvement. Like, I've now been to America and Canada three times but, to the best of my memory, the recording company haven't even given me the courtesy of coming to my gigs. First time round I found that quite hurtful but I've learned to live with it now and it doesn't bother me at all."

The fundamental point about Unfinished Revolution is that it seeks to mate a persuasive, almost conversational, musical tone with his most uncompromising set of lyrics. The jester Christy of songs like 'Lisdoonvarna' and 'Delirium Tremens' takes a sabbatical to be replaced by Moore at most broodingly political in bleak scenarios drawn from across the Irish and International agenda.

One comment may be symptomatic of his gameplan on Unfinished Revolution: "It's basically a matter of finding a way of making something, that's in a way very painful, making it palatable and trying to draw people into something they don't want to hear about."

There's a difference between giving opinions in interviews and performing?

"Yeah, as for the first, no problem, but if you're getting up on a stage in front of maybe a couple of thousand people who've come for a night out and you want to provoke them to think about something, you have to do it in a certain way, you have to bring them in. Touch their hearts with it, rather than a confrontation."

He also believes the album has "my own best writing to date. The song about which I'm happiest, of anything I've ever written, is 'Derby Day'. It's only two minutes and twenty seconds long but I consider it to be like a play."

But writing can be a grind - a surprising revelation from a man who regularly tosses off impromptu cameos. "They're a cinch," he explains. "Basically all you need for those songs is an initial concept. Then the rest is so easy. But the other songs - well, 'On The Bridge' took me six months hard work and it's only two and a half minutes.

"And 'The Other Side' took me a year. I have copybooks full of verses of that song whereas, at the end of the day, the second last verse of that song took me about three minutes. I had a lot of trouble with it. I had to record it three times. There were a lot of potential libels. As a result of the Stardust song, this album was given severe scrutiny at various levels. In one case I had contemplated giving the credits to one particular song as music: Christy Moore and words: Christy Moore and then list about 48 lawyers who had fine-combed it. But at the end of the day, it didn't matter because each time the song was sent back to me, it actually got stronger."

Drawing people in, making the painful palatable, Moore offers 'On The Bridge, whose theme is the strip-searching of women in Armagh Prison, as an example of his method.

"The difficulty about that was, it was about something Irish people in general don't seem to want to hear about. Trying to confront Irish people with the humanitarian issue of strip-searching, I wanted to draw people into a song before I told them what it was about. We don't actually find out its topic till the end of the chorus, two-thirds into the song. It's interesting the response when I do it at gigs. Sometimes I get the response, 'Oh Jaysus, this is not what it's about'. There are people who don't want to know and I don't blame them, but I'm just trying to make them think about it."

In songs like that, the title track, 'Derby Day' and 'The Other Side', the album also explores women's issues, an innovation in his work Christy Moore believes was long overdue. He admits, "I wasn't aware of women's oppression when I was 11 or 21 or 31. But maybe about 31, I became aware. I remember about that time playing up North and being savaged for singing 'A Bunch Of Thyme' and it set me thinking. And even though there are times when militant feminists in the audience will wrongly pick loopholes in things, sometimes they also pick loopholes rightly."

But why should his most militant album be released in 1987 and not at any time in the past five years. Perhaps albums surprise even their creators as they develop. Christy dismisses any notion of a masterplan.

"I don't sit down and say, in two years time, I'm going to do a serious album. I just take it as it comes along. This is how it evolved and I'm very happy it has evolved this way. The same with Ride On and Ordinary Man. Like with Ordinary Man, I was kind of going for a certain atmosphere and sound and I suppose it was some response to Moving Hearts."

On the subject of his earlier albums, he's in no way apologetic. "Though some of the songs were quite pointed, in general, they were lightish albums which I'm very happy with. But there wasn't so much meat on them. It just happens this album is different."

First and foremost, Christy Moore may be our most consummate live performer. A throwback to the days when lighting designers were an unknown species, there's none who can range across such a spectrum of feeling with the sole aid of a guitar and a microphone.

He still doesn't tire of the experience. "I do say to myself I don't want to drive for five hours, I don't want to get on a plane, I don't want to do an interview or I don't want to have my photograph taken - but I never say I don't want to play. It's my life's blood."

What's the performer's urge in you?

"I love that thing that exists between a performer and the audience, that magical, intangible thing which is created. That you cannot measure or see or feel or touch. It really turns me on. Things like a good heckler. Every night something happens that has never happened before and will never happen again. It's like walking a line. Sometimes it feels quite dangerous and sometimes, there's very strong emotion of different kinds. I have found myself in situations wondering if I'm going to get to the end of a song because I was being so emotionally affected.

"Sometimes it could be with a song that I've sung for years and years, but on a particular night, something will happen. I can remember one night in the Hammersmith Odeon singing 'I Pity The Poor Emigrant' and I thought I was going to choke."

The lighter side is Christy's wily way with a heckler. He can welcome them - though don't all rush!

"Provided he's a guy who's not totally out of his brains. Or I should say a person out of their brains because some of the most vicious hecklers tend to be women - especially drunk militant, separatist feminists. They are the most severe of hecklers!"

But he pauses: "A good heckler is worth its weight in gold. Wonderful. And there are hecklers whom I recognise, I've never met them, I don't know what they look like but I know their voices very well."

He claims his experience with Moving Hearts transformed his style. "I'd say I learned more from that than from any other band I was in. In Planxty, I was always in awe. In Moving Hearts, I definitely developed rhythmically, as well as developing a lot more confidence in myself as a singer. I developed confidence in my judgement about lyrics and, finally in Moving Hearts, I no longer saw myself as a traditional or folk singer. I no longer feel myself folky-folky-folky."

"Folky-folky-folky"! Pray define?

He reflects: "I don't feel precious about it. Folky-folky-folky is too precious. Donal Lunny describes it as treating music and songs as museum pieces to be taken down and polished and put up again. There used to be a time when I worried about what people in traditional clubs thought about me as a singer. I used to be in awe of the sean-nós thing.

"But now, I don't give two shits about it. I like them as people, I admire them and I go to hear them, but I don't worry about what they think of me. I still sing traditional and unaccompanied songs but I did a thing a few years ago which in a way was a great cleansing. I Actually got rid of all my old song-books.

"That was a conscious effort to force myself to write modern songs - though, since then, I've got a few of them back, mind." (laughs)

Unfinished Revolution must be Christy's umpteenth collaboration with Donal Lunny, to whose abilities he pays fulsome tribute.

"Donal Lunny taught me how to play guitar when I was 16 and he was 14. He was drumming in a band in Newbridge. He's by far the most important person in my musical life, even though sometimes we don't see each other for months. On a human level, I would regard him as my best male friend. After my wife and mother, he would be the person who understands me most, in certain ways.

"Musically, he's the mainman. There's no doubt that for me, he's the most important Irish musician for this time, maybe for all time... I look forward to the day when Donal gets enough space in his life to write seriously. He's been diluted by the amount of work he's done. I think he does urgently need to learn to say No - which is something I had to learn. It's a very big word."

He remains unswerving in his choice between Ireland and any international market. "Ireland," Christy Moore says, "is where I operate and get my inspiration and encouragement. It's where I like to be. I don't want to be anywhere else. There's very few situations that arise in Ireland that I can't handle."

As for abroad, he says, "I'm not really trying to do anything. When I go to Australia and America, I always want to go there to broaden my horizons, to see how these places function and get an insight into American society. Like, if I never sell another record in America, I wouldn't lose any sleep over it. I can honestly say I prefer playing in Kerry rather than America.

"If I get an American release and sell 100,000 records, there'd be nobody more pleased than me. But it's not an ambition because I learned from way back - I've been kicked in the teeth so often with Moving Hearts and Planxty. If you lean back so far to achieve certain things, you lose what you had in the first place."