San Francisco's Kronos are not your typical string quartet, having dabbled in styles ranging from Hendrix to Mingus. Violinist David Harrington tells Arminta Wallace about the group's desire to keep pace with new sounds

It's first thing in the morning, but David Harrington is already up and at it. The Kronos Quartet, he explains, is recording a new CD. "We've got four more days of recording and it's been, oh, 18 hours a day or something like that. But it's a good time to talk, because I'm feeling so inspired about things I can hardly stand it," he declares.

Wow. Must be pretty powerful stuff? "It is," he says. "It's an album of songs by R.D. Burman. He was a film soundtrack composer who died about 10 years ago, and we're doing 12 songs, arranged and played by us along with his wife Asha Bhosle, the queen of film soundtrack singers. If you can imagine a mixture of the melodic genius of someone like Schubert, the orchestrational genius of someone like Debussy or Stravinsky, the pop sensibility of someone like George Gershwin. And then you add the power of Asha Bhosle's voice, which is . . . man. It's sort of like Aretha Franklin or something. I'm telling ya, I'm inspired right now. Oh boy."

You might describe this as a typical Kronos project - an album of Hindi and Bengali love songs, written by a man who is almost totally unknown in Western classical music circles and sung by a woman who has sold more albums worldwide than Elvis and The Beatles put together - except that when Kronos comes in the door, "typical" goes out the window.

Since it was founded in 1973, the quartet - which currently consists of violinists Harrington and John Sherba, viola player Hank Dutt and cellist Jennifer Culp - has performed just about every style of music imaginable. At the rock end of the spectrum they've played Jimi Hendrix and worked with David Byrne of Talking Heads fame. They've commissioned hatfuls of new works from classical contemporary composers such as Sofia Gubaidulina and Zhou Long. They've even recorded an album of rambunctious folk music with musicians from Mexico.

Which begs the question: do they ever pretend to be a regular string quartet and play a programme of Haydn, Schubert and maybe, just to be really daring, Shostakovich? "You know . . . " begins Harrington. He pauses, before chuckling. "I really appreciate that music and those composers and all that, but we haven't done that sort of programme for 30 years. In the very earliest days, perhaps. But Kronos has been too busy worrying about the next sound, the next step, the next relationship with a wonderful composer. We've got our work cut out for us just to keep up with that."

It seems as if everybody who is anybody (musically speaking) wants to write for Kronos. At the moment the grand total of composers writing for the group is somewhere around 45 - and that's not counting the wannabes. "Yeah well, I'm here in the office, and I'm looking at the box of scores that I haven't looked through yet, and I'd have to say it's pretty big," Harrington says with a rueful laugh. "And I've been behind for so many years that I think the only way to catch up is to live a really long time."

Irish audiences, meanwhile, are about to get the opportunity to do some major catching up with Kronos. The programmes for the quartet's two concerts at the O'Reilly Theatre in Dublin on September 15th and 16th are, to put it mildly, eclectic. How would Harrington put it? "What we'd like to do," he says, "is play some of our favourites from the last few years, and then some new pieces that we find really beautiful and engaging, and so give a sense of the expanse of our work."

The first programme opens with one of R.D. Burman's songs, Tonight is the Night, and wends its merry way through music by Franghiz Ali-Zadeh, Steve Reich and Charles Mingus. Harrington chuckles again. "Oh, yeah - we're playing some of my favourite stuff, that's for sure. I don't know how much Mingus you've heard, but when he hits a home run, it goes a mile.

"Franghiz Ali-Zadeh is from Azerbaijan, and she's writing such beautiful and inspired music - we just wanted to be sure that our audience in Ireland knew of her work."

The music on the second evening ranges from a new string quartet by the South African-born (but Dublin-based) composer Kevin Volans to a piece that goes by the intriguing name of Potassium. What's that all about? "Potassium is by Michael Gordon, and it's - now how would you describe that? If you think of music as a spectrum of many different things, it definitely comes from the part of the spectrum that would include lots of electric guitar sounds."

The quartet Black Woman Rising was composed by Volans as a bookend to a piece called White Man Sleeps, which he wrote for Kronos in 1985. "It's a super-charged piece," says Harrington. "We premiered it in Chicago in June and then we played it in Italy, and other than that, it hasn't been played that much. We've been busy making this record since then. Yeah, we're very anxious to play it."

For the second half of the second programme, the quartet will be joined by the trad box player Tony MacMahon for a selection that will include arrangements - by MacMahon and Kronos regular Stephen Prutsman - of such well known tunes as The Battle of Aughrim and An Buachaillín Bán.

"I first heard Tony the last time I was in Dublin," says Harrington. "It was actually during the debates for our presidential election in the fall of 2000. The night I heard Tony was the night of the first debate between Gore and Bush. He did a theatre show, a programme of the diaspora of Celtic music.

"It was fascinating, and every time he started to play I just couldn't believe what I was hearing. We got to meet after the show, and then my wife and I went back to the hotel and stayed up real late to watch this damn debate. And it was odd that Gore had underestimated that imbecile. We got so depressed. Then we put on Tony's CD, which was, well, the way that man plays, his melodic genius - even after something as depressing as that debate, it made us feel better."

The idea of music as an uplifting force with transformative powers is an integral part of Harrington's artistic credo, and his interest in the effects of exile and return on Irish music finds an echo in his conviction that living and working in San Francisco has been a crucial influence on the Kronos Quartet.

"San Francisco's an interesting place. There is this sense of exploration and examination here. I think all of us in Kronos feel empowered, not only by the great tradition in music here - the jazz and pop music that was happening here in the 50s and 60s, the 70s and 80s - but also by the poetry and by what has happened in the arts generally. There's kind of an energy that we get from here. It's hard to describe, but every time we come back I can feel it.

"It's not only that our families are here, but I think that San Francisco is a place that gives us a kind of a different look at our own American society. It allows us to view the east in a way that is hard to do from, you know, Dick Cheney's home town, for example."

A little unfair to Lincoln, Nebraska? Perhaps. But what Harrington absolutely rejects is the notion that Kronos has deliberately set out to blur genres or break boundaries. He and the other members of the quartet, he insists, simply play music that interests them, in the company of other musicians who interest them.

"I've always just used my own instinct. My own ear. That's all you have, after it's all said and done, and so far I can trust my ears." Ears, he adds, don't know anything about musical boundaries. "I don't believe the ear works that way. You absorb all kinds of different music in your life. Some of it really reaches deeply into your life, and that's the music that stays with you."

According to Harrington, music can capture the specialness of each moment like no other art. "I want our concerts to be celebrations of creativity, of that special spark of energy and imagination. That's thegreat thing about music, you know? There are so many places it can go. I feel like we're living in an incredibly dangerous moment in human history. Things feel like they're kind of on an edge.

But I'm glad that we've had all the experiences that we've had, because it seems to me that we can move through this difficult time. I almost feel like Kronos can be an antenna, or something like that, and capture some of the really important music that is happening right now. It's a good time for music. And it's a wonderful time to be a listener."

• The Kronos Quartet will play at the O'Reilly Theatre, Dublin, on September 15th and 16th. They will be joined on the second night by Tony MacMahon. Kronos will also play in Cork on May 13th and 14th next year as part of the Cork 2005 celebrations.