An Irish connection has always been central to the success story of Nanci Griffith. Indeed, her career in Europe got its kick-start when she had a number one here hit in Ireland with From A Distance in 1987, the same year she performed in the ground-breaking RTE series, The Session - which, according to its producer/director David Heffernan "set out to highlight the links between American country and Irish folk music" and where she was teamed up with Mary Black, one of the Irish singers who had championed Griffith songs.

Nanci readily admits that her fame in the United States "really took off" that same year when U2 told Rolling Stone she was one of their favourite artists - which probably makes it all the more fitting that U2's bassist, Adam Clayton, and drummer Larry Mullen Junior would later play on her album Flyer. That album also featured The Chieftains and was largely composed during what Griffith describes as "a pivotal period" in her life, during the mid 1990s, when she was living in Dublin.

But then, in a more obvious sense, Irish musicians have backed Griffith from the beginning. Guitarist Philip Donnelly even describes himself as the "founder-member" of her Blue Moon Orchestra. Griffith herself says that drummer Fran Breen "became a wall of drum and percussion" behind that legendary ensemble. And this Irish connection continues with her latest album Other Voices, Too (A Trip Back To Bountiful), which was recorded, in part, in Dublin, and also features Irish musicians Dolores Keane, Nollaig Casey, Mary Custy and Sharon Shannon. For the accompanying book, Nanci Griffith's Other Voices - a Personal History of Folk Music, Griffith also chose an Irish photographer, Gerry O' Leary, to document those Dublin sessions and, clearly exhibiting a lapse in good taste, an Irish co-author, namely myself. In fact, Gerry O' Leary's photograph, which accompanies this article, was to have been the cover shot on that book. And should have been. Not only because it captures, as I say in the preface, "the spirit of music, the spirit of art as an emotional imperative, and the spirit of a singer acting as a conduit for everything that is transcendent and true" but because it also captures the essence of that force that is Nanci Griffith. So, what, exactly, was Nanci feeling as O'Leary's camera clicked while she and co-producer Jim Rooney were listening to the playback of arguably the finest, if not definitive, song from her new album, Stephen Foster's Hard Times Come Again No More?

"I have this old Saint Christopher medal that was given to me by my boyfriend when I was 12, and when I'm really hopeful or really intense, it always ends up in my hand," she confides, sitting cross-legged on the floor of her home in Franklin, Tennessee and, tellingly, referring to the young man whose death, as a result of a motorcycle crash at the age of 17, set in place many of the psychic shadows and ruptures she rarely talks about, but which rise time and time again through her music. "You can see from that picture of Rooney and me that we are so happy with what we're hearing. When Dolores Keane's voice kicked in on that line Hard Times Come Again No More she was that song's `pale sorrowed maiden.' She is the soul of Ireland. You can hear her crying. And everyone at the session was crying. It was a powerful moment. And the fact that Nollaig Casey and Mary Custy were playing from Stephen Foster's original charts, really brought the whole thing back to basics - back home in every sense. We felt we had brought Stephen Foster back to his ancestral home of Ireland. It was that magical."

Cynics, of course, might say this is all sentimental slush. Far from it. Nanci Griffith is not alone in her belief that Dolores Keane's voice, at its best, can personify "the soul of Ireland". Nor could Nanci be accused of twisting history out of shape to hype her own album. The ancestors of Stephen Foster, the "father of American popular music", did come from Belfast. And Casey and Custy were playing from Foster's original music charts simply because that's what Nanci secured from the Stephen Foster museum rather than record any of the versions that were later bastardised in the name of pop. That said, she and I did collide on her belief that Hard Times Come Again No More dealt specifically with the Irish famine, a notion she passed on to all musicians during the original recording session. Actually, the song also was inspired by Charles Dickens's novel Hard Times, a fact Nanci now acknowledges, somewhat reluctantly. "He originally wrote an operetta about the potato famine, but this is the only remaining piece of music from it," she asserts. "And, as a singer, you do have a responsibility to live up to the songs, not to let down the writers, the musicians, their history, everything. And the atmosphere that Sharon, Nollaig and Mary created really was so moving. Yet I have to say that you wouldn't hear my voice break if we had known, at the time of recording that song, that it was based on the Dickens's novel. I had been told it was about the Irish potato famine and everyone in the studio that day was thinking of that - especially, obviously, someone like Dolores. So even if that turns out not to have been Stephen Foster's inspiration for the original song, the idea of the famine and the suffering of millions of Irish people was on our minds when we recorded Hard Times Come Again No More. And in our hearts. It's definitely what you hear in my voice." Though definitive in terms of the album, Stephen's Foster's song is only one of 19 tracks on an album that is the companion-piece to Nanci's 1993 album, Other Voices, Other Rooms, with which she set out to rediscover, and help audiences reconnect with, folk music. Another track, Richard Thompson's Wall Of Death, also recorded in Dublin, forms the opening salvo on the new album, she claims, "to announce another journey and show that we want to begin with modernism, with folk music meeting rock music in the 1950s and the 1960s". This particular recording also links Irish and British culture in a way that may even make politically acceptable and legitimate, that loaded phrase "the British Isles". At least, in terms of folk music.

"Dublin was important because we wanted to bring in my favourite Irish musicians and also the British side of folk music," Nanci explains. "For example, Clive Gregson, who used to play with Richard Thompson; Brian Willoughby from The Strawbs; and Ian Matthews, an original member of Fairport Convention. On Wall Of Death you can hear Sharon [Shannon] playing that carnival accordion and playing off Clive Gregson's guitar, and it is totally incredible. It also highlights my belief that this is not so much a Nanci Griffith project as a group project, all of us musicians and songwriters - past, present, dead and alive - working together."

In other words, this is an album of folk music, in the purest possible sense. With songs from folk, country and well-known pop icons such as Pete Seeger, Woody Guthrie and Johnny Cash, to lesser-known writers like John Grimaudo and Millie Merkins. Nanci categorically rejects the suggestion that those in the latter category were chosen because they are her buddies, saying "They are there because they belong on this album". Either way, no one is going to argue with her inclusion of a contemporary folk masterpiece such as Sandy Denny's Who Knows Where The Time Goes? which was the third of the three tracks recorded in Dublin and one that, again, seems to crystallise what her new album is all about. Particularly in terms of Denny's voice, which clearly moves Nanci Griffith at a core level. "Coming from Texas it was the first time I'd ever heard a voice like that," she says, gazing through her window at the Tennessee twilight, as if she could actually see all the way from here to Austin, Texas. "Of course I'd heard people like Odetta and Rosalie Sorrels, growing up, but it was the first time I'd heard someone from that tradition. It's like if you go back and listen to Dolores Keane with De Dannan there is something magical about that voice, like the soul, the spirit, driving through her body into yours. You can feel it. You can feel Sandy Denny's breath on your neck, even though she now is dead. That, to me, in the end, is the real magic of music. Folk music."

Nanci Griffith's Other Voices: A Personal History Of Folk Music by Joe Jackson will be published by Random House, New York on September 14th.