There are several reasons to admire the Kronos Quartet, and, unquestionably, the primary reason is their extraordinary talent. But I'd like to add two more: their musical and professional integrity, and their belief in music as a spiritual quest.

Since 1973, when David Harrington founded the group after hearing a performance of George Crumb's response to the Vietnam War in the form of a string quartet, the Kronos Quartet has been a major mover and shaker of contemporary music. Their mission has been to expand the standard string repertoire to include works inconceivable to most of their classical music comrades. Over the past 28 years, the group has commissioned and premiered more than 400 new string quartets by composers spanning six continents and at least four generations.

The number of works commissioned by the quartet amount to more than twice the number of string quartets composed by Haydn, Mozart, Beethoven, Schubert and Brahms combined. The first came from Harrington's former teacher, Ken Benshoof, and was commissioned for a bag of doughnuts. The group's recording of Crumb's "Black Angels" (Elektra/Nonesuch, 1990), the work that inspired this feat, is now considered a milestone of contemporary music. More than a decade later, Kronos continues to amaze as they ascend to higher levels of artistic excellence.

Reaching a wider audience than commonly expected for contemporary art music, Kronos attracts new listeners and transforms our expectations with each performance. The list of Japanese composers alone whose quartets have been performed by Kronos is impressive: Hirokazu Hiraishi, Michio Mamiya, Akira Nishimura, Somei Satoh, Toru Takemitsu and Joji Yuasa, to name a few. Arrangements of music by Charlie Mingus, Howlin' Wolf, Jimi Hendrix and scores by composers relatively unknown to or ignored by the predominantly Euro-biased world of classical music have become a regular, and expected, part of their programs.

All right, anyone can get funky, but Kronos has almost single-handedly resurrected contemporary (and arguably classical) music with a vivid imagination that transcends a highfalutin and largely predictable territory. The Kronos Quartet has a vision. Music is an active backdrop for the quartet's liberal, and generous, social and political views. The members have recorded more CDs in the past five years than most artists record in a lifetime; they chat with fans over the Internet and actively promote the arts.

As politicians cut funds to public schools for the performing arts, the members continue to give concerts to schoolchildren. Violist Hank Dutt explained: "The members of the Kronos Quartet started music in [public] schools, which were well-funded in the beginning. I am appalled at how the funding is not there anymore. Every chance we get, we try to play in the schools to give back what we were given as budding musicians."

In simpler terms, Kronos has propelled the string quartet from its position as background music into musical activism in the foreground.

The Kronos Quartet Japan Tour 2001 will be a cross-cultural experience. This year, they will perform a total of five concerts in Tokyo, Yokohama, Osaka and Mito. Arrangements of music by the legendary Argentine bandonionist An'bal Carmelo Troilo (1914-75), jazz great Charles Mingus, and the influential and versatile Indian music director Rahul Dev Burman ("Pancham" 1939-1994) are placed between "Cortejo Funebre en el Monte Diablo" and the second movement of Terry Riley's powerful elegy "Requiem for Adam" (1998).

"Oasis" (1998), a work included in the "Silk Road" cycle of Azerbaijan composer Franghiz Ali-Zadeh; "Quartet No. 4" (1999), by Latvian composer Peteris Vasks, based on motives from Latvian folk songs; and "Pannonia Boundless" (1998), by Yugoslav composer Aleksandra Vrebalov, all illustrate the great variety of musical creativity found in the former Soviet states. All this is coupled with contemporary works by Steve Reich, Arvo Part, Clint Mansell and P.Q. Phan.

Those who will miss the concert series will be able to catch Kronos' performance of Clint Mansell's score for Darren Aronofsky's film, "Requiem for a Dream," premiering in Tokyo at the end of this month. Mansell, a founding member of the English rock band Pop Will Eat Itself, first worked with Aronofsky in 1997 on the original music for his earlier film, "Pi."

This time, his sensitive score is magnificent and weaves in a perfect blend with Aronofsky's disturbing film. Set on the streets of Coney Island in Brooklyn, the film and music take us on a harrowing journey into four people addicted to the visions of a happier life.

Kronos' performance is superb, incredible in its energy, empathy and sensitivity. Very few musicians could do any better. They drive the music forward with a thrust and pull you into the drama in a psychological spin. This music is not suited for humming or whistling, but forces you to pay close attention and experience the swirling visual and aural action. By the end of the film, my heart was beating and my knees were weak, and I must confess that a large part of my palpitations were caused by Mansell's music. I wonder how long it took Kronos to recover from the physical and emotional strain of such a performance.

Then again, perhaps Kronos' members take all this in stride. David Harrington once summed up the way he and his fellow members approach music this way: "I've always wanted the string quartet to be vital, and energetic, and alive, and cool, and not afraid to kick ass and be absolutely beautiful and ugly if it has to be. But it has to be expressive of life. To tell the story with grace and humor and depth. And to tell the whole story, if possible."