USING WORDS to describe music is at best an exercise in metaphor. For example, "Convergence," the title of this coming Saturday's New Music Works concert, doesn't quite cut it as promotionese. "Convergence of Legends" would have grabbed more attention and actually gets closer to the truth, because outside our provincial precincts, the participants are known for star mystique in their fields of special endeavor.

The composer Alvin Curran has been a force in avant-garde music and "installations" for nearly five decades, particularly in the United States and Italy, and brings to the party "a volatile mix of lyricism and chaos, structure and indeterminacy, fog horns, fiddles and fiddle heads." Harpsichordist Linda Burman-Hall is widely recognized for her scholarship in Baroque music and understated adventures at the cutting edge. For decades, percussionist William Winant has been the first choice of every composer of new music west of the Mississippi, premiering countless original commissions. Violinist Timb Harris enjoys a similar reputation for his advocacy of new music with Estradasphere, the widely traveled and recorded, stylistically eclectic Santa Cruz-launched band. And, up until she stepped aside in 1999, cellist Joan Jeanrenaud was one quarter of the truly legendary Kronos Quartet.

For Saturday's concert, at UCSC Music Recital Hall, Jeanrenaud teams with regular colleagues Curran (on keyboard electronics) and Winant for the world premiere of Curran's Passing Notes. The program also includes two major keyboard works by Lou Harrison (one for harpsichord, one for tack piano, each with its own special tuning) featuring Burman-Hall, and John Cage's Four6 for cello, percussion violin and electronics.

After leaving Kronos, Jeanrenaud had improvisation on her mind. "I found myself in a different place," she explains. "Ninety-nine was my sabbatical year. It became clear that I was happier not being in the group. Kronos travels so much—their schedule had become daunting—and as a musician I wasn't learning anything anymore. I wanted to explore." It was in that time that Jeanrenaud was diagnosed with multiple sclerosis. "Now I see it was the MS. I had my first episode in '96. My health is really good now but I have a weakness in my right leg." Still, she adds, "Artistically, I was ready for a different direction."

Since her early training, Jeanrenaud has nurtured a hearty interest in improvisation and jazz, and studied them at Indiana University. But after joining Kronos, that interest took a back seat. After Kronos, she worked with sax players Hal Stein and Larry Ochs, and studied with the Rova Sax Quartet. "All my composer friends said if you start improvising pretty soon you'll start composing," she says with a smile and a shrug. Meanwhile, she teamed up with Ochs and koto player Miya Masaoka to perform and record. And she began to compose in earnest. Owing to her two decades with Kronos, she wrote a lot of music for four parts, then seven and now even more. A new CD of her works, Transitions, includes arrangements of Baroque composers Marais and Telemann, plus Philip Glass.

One on one, Jeanrenaud is naturally personal and refreshingly unguarded. But there's toughness under the easy charm, as represented not least by her artistic credo: "I am a cellist dedicated to experimentation and innovation in the arts."

I asked Jeanrenaud to describe the new Curran piece. "Sometimes it's in unison," she said, "then diverges, on both stopped strings and harmonics. Its unisons then drift slightly apart, going out of phase. Timbres give it lots of color." Then, from a different vantage, "It starts thin and keeps building, in both activity and density. Willie has some loud hits, then I come in soft—pretty much me building while he adds." Lasting about 20 minutes, its expressive content "takes care of itself," Jeanrenaud says, adding, "When I have a solo part, it's really high, and intensity dramatic."

In talking about music, metaphor works on one level. But you can never go wrong with a detailed action plan.

New Music Works presents Convergence Saturday, Jan. 20, at 8pm at the UCSC Music Center Recital Hall; tickets $18 general/$15 senior/$12 student. (831.459.2159)

Send a letter to the editor about this story.