What is Jewish music?

The 16th annual San Francisco Jazz Festival will confront that question Saturday and Sunday, Nov. 7 and 8 in two concerts titled "Riffs on Tradition."

The performances, featuring a cross-section of music by contemporary Jewish musicians, will take place at Congregation Emanu-El.

The first night is headlined by the Andy Statman Quartet and features Kaila Flexer & Third Ear. That show is being called "Music of the Hebrew Mystics." At the following night's show, "Radical Jewish Culture," the John Schott Group opens for John Zorn's Masada.

The festival, which opens Thursday, will also present a free dialogue at 10 a.m. Saturday, Oct. 31 with Flexer and Schott on the links between Jewish music and jazz, at the festival store and gallery, 2 Embarcadero Center, S.F.

Schott, a Berkeley guitarist and composer, sees the whole enterprise of defining a pure category of "Jewish music" as something of a fiction. "All Jewish music was always a combination of many sources. For example, cantorial singing took a lot from opera, klezmer took a lot from Greek, Bulgarian and Russian sources," he says.

Schott's view is also informed by his eclectic musical background and experience. "I'm a classical composer with a degree in classical music, but I've made my living as a jazz guitarist for the last 15 years."

Opening for Masada, Schott's quintet will premiere a new work combining Hebrew and English texts, jazz and classical music, built around the 1928 poem "Ashrei Harozim" by Avraham ben Yitzhak, generally recognized as the founder of modern Hebrew poetry.

In this piece and in his work generally, Schott is clearly stretching tradition to incorporate new forms. "I love traditional Jewish music but that's not what I'm doing," he says. "My hope is that people are open to a generous definition of Jewish music."

For Statman, a New York-based clarinetist, "Jewish music" doesn't exist on its own, for its own sake. Its defining purpose "is to induce a spiritual experience, to bring you closer to God." For this reason, he says, "Jewish music is entirely functional."

Growing up in a secular household, Statman achieved his early success as a bluegrass mandolinist in the mid-1970s and later as a clarinetist and driving force behind the "neo-klezmer" movement, which remains hugely popular with Jewish audiences. A protégé of deceased klezmer great Dave Tarras, Statman began playing klezmer in the late 1960s, long before it was fashionable.

Since that time, Statman has had his own klezmer orchestra and produced a steady output of traditional klezmer recordings. Bay Area audiences, however, may know Statman best for his work with mandolinist David Grisman, most recently on the 1995 CD of traditional Jewish melodies, "Songs of Our Fathers."

Although Statman still plays some klezmer, he's basically moved on. "The problem that people don't understand is that klezmer doesn't really have a living context anymore; it was the music of a certain time and place that's gone," he says.

The music on his last two recordings, "Between Heaven and Earth," and "The Hidden Light," has been called "Jewish jazz." Although it sounds like traditional jazz at times — and Statman's quartet has been known for its extended flights of live improvisation — the music is firmly grounded in Chassidic vocal tradition.

"The melodies we play all come from this tradition. It's a living unbroken form going back hundreds of years and it's still thriving," Statman says. He adds that all the tunes he plays are really niggunim (wordless melodies) designed to induce a spiritual experience. "These are melodies that we sing in the house and the shuls I pray in."

When playing live, Statman says, he and his quartet hope "to take people on a spiritual journey." Simultaneously, "When we get up to play we never know what's going to happen; we try to keep the music as open and spontaneous as possible."