ELIZABETH FARNSWORTH: In the years since the group began in 1973 Kronos has redefined what it means to be a string quartet. They respect and sometimes play the more traditional string quartet repertoire - music by Haydn and Mozart, for example - but new music, often from Africa or Asia, is the group's passion. It's a passion audiences apparently share. Kronos is one of the classical world's biggest draws in CD and in live concert. At this sold-out concert November 1st in San Francisco, Kronos premiered an opera by Vietnamese-American composer P. Q. Phan, an opera without voices. Each instrument took on a particular role throughout the work.

The quartet also played "Waterwheel," a signature piece which they commissioned from Sudanese composer Hamza El Din. It's a tribute to his village, lost to flooding when the Aswan Dam was built. He accompanied them on drum and lute. One reviewer wrote that Kronos has blown the whole concept of chamber music off the shelves and onto the charts. Their clothes and style set them apart from most other string quartets and help attract younger fans. They finished every one of the last ten years with a CD on Billboard's Top Ten Classical Chart. In 1994, the magazine CD Review named Kronos one of the top ten performers of the previous decade, along with the three tenors and Madonna. During intermission in San Francisco fans were enthusiastic.

CONCERTGOER: They have a distinct style. They have a distinct quality. And they've also got - there's sort of a rock star thing about them too.

CONCERTGOER: Well, I think these people have been great for years and years and years. They've been doing wonderful stuff. They've committed maybe 400 works, I find out, they commissioned. And I thought there was brilliant stuff in there.

ELIZABETH FARNSWORTH: Last month, in honor of their 25th anniversary, the group released a 10-CD retrospective featuring, among other early works, "Black Angels." (music playing in background) It's a searing, anti-Vietnam War quartet written in the early 1970s by composer George Crumb for amplified strings and percussion. The music inspired violinist David Harrington to found Kronos.

ELIZABETH FARNSWORTH: What was it about the George Crumb piece, "Black Angels," that show - that hit you so hard, made you want to start a string quartet?

DAVID HARRINGTON, Kronos: Well, in 1973, I heard this piece by accident late one night. And I would advise anybody that has a chance to hear "Black Angels" to hear it late at night by accident and turn it up really loud too, because it's scary, and it's wild, and it's beautiful. And it challenges your ideas about life and music and everything. And that's what happened to me. And this was at a time when the world didn't make any sense to me. And I couldn't find any music that felt right. All of a sudden there was this music, and I felt like I had a voice, and I had to play that piece. And in order to do that, there had to be a group that would practice every day and would really devote itself, because it's a very complex undertaking to realize that music.

ELIZABETH FARNSWORTH: You had long loved the music of string quartets, right?

DAVID HARRINGTON: Yes, since I was 12 years old, when I first heard the Budapest Quartet on record. Some kids play in garage bands and some kids play in polka bands, and some kids play in string quartets. And that's what I did. And for me, the sound of the string quartet has become the sound that I think with, I think, and so for me, it's become a very personal form of expression.

ELIZABETH FARNSWORTH: From the beginning, Harrington commissioned new works. He and the other members of the quartet, Joan Jeanrenaud on cello, Hank Dudd on viola, and John Sherba on second violin, work closely with each composer, as they did with P. Q. Phan on his opera.

DAVID HARRINGTON: It would be a lot easier to hit the "B", just the "B."

ELIZABETH FARNSWORTH: Since 1973, the group has commissioned and premiered 400 string quartets from composers spanning six continents and four generations, more than twice the number by Haydn, Mozart, Beethoven, Schubert, and Brahms combined.

ELIZABETH FARNSWORTH: Describe the genesis of the P. Q. Phan piece.

DAVID HARRINGTON: It was about four years ago in Iowa City. We were playing there, and Phan came to one of our concerts, and we started talking afterwards, and it became really clear to me that I should hear this guy's music. And so he sent some tapes. And immediately it seemed to me that here was a composer with just an amazing amount of skill and ability, and later he and I met again, and we began to talk about personal things. And it became quite clear to me at that point that he was trying to avoid his past. He had basically tried to forget about his earlier life, and I think I remember saying to him that the only way we're really going to grow through experiences is to use them and confront them and somehow deal with them.

ELIZABETH FARNSWORTH: You edit - in a sense - you get music from a composer and then you and the other musicians kind of work with the composer and edit, is that how it works?

DAVID HARRINGTON: For us, musical notation is not an exact form of communication. We value the voice, the body language, the experiences of composers to help broaden our own ideas of life and music. And so for us what we do is assemble evidence, human evidence that is expressed in music, and try to examine some of the mysteries.

ELIZABETH FARNSWORTH: What about your sound, how is it different from the sound that you would have made playing in a string quartet, playing Haydn in a string quartet in 1971?

DAVID HARRINGTON: Well, you know, I think if Haydn would have come in contact with African music and tangos and Asian opera music, and I think that he would have had a very much different sound than he had in his quartets.

ELIZABETH FARNSWORTH: You have a certain sound. It's very difficult for some listeners, as you know. Partly the music is - some of the music is very modern in ways that they're not used to.

DAVID HARRINGTON: If our sound needs to be uneasy and brash and rough, then it will be as brash and rough as we can make it. If it needs to be soothing and comforting, it will be as soothing and comforting as we're capable of doing. (music in background) For me, music exists in notes, and a note - it's possible to put your entire life's experience and knowledge into notes with a great deal of focus and concentration. And it doesn't happen very often. In fact, for me, it's maybe happened three or four times in my whole career when I felt that "a" note was getting close to a certain real essence of expression. (music in background) It's those moments, those real high moments of focus that we look for, I think.

ELIZABETH FARNSWORTH: Kronos is celebrating its 25th anniversary through the end of the year with performances in Germany, France, and Poland.