Over the past quarter century, the Berkeley-based Jewish Music Festival has showcased the spectrum of Jewish music from around the world, from centuries-old cantorial melodies to hip-hopping contemporary klezmer, Moroccan grooves and Cuban-Jewish fusion. It brought Arkady Gendler, an octogenarian Yiddish singer from Ukraine - and recorded his vanishing pre-World War II repertoire - and an oud-playing Iraqi who's keeping Iraqi Jewish music alive in his adopted home of Israel.

To celebrate its 25th anniversary, the festival has booked an intriguing mix of sounds. It opens Saturday night with a performance of sacred Jewish and Muslim music of the Middle East by the Yuval Ron Ensemble, joined by a Sufi dervish. There's the American premiere of Diaspora Redux, a stellar group of improvisers from Berlin, Buenos Aires and New York who meld jazz, tango and klezmer. Grammy-winning singers Susan McKeown and Lorin Sklamberg perform Jewish and Irish songs dealing with "love, death, betrothal, betrayal and the demon drink."

We talked with festival director Ellie Shapiro about the tradition and evolution of the oldest major Jewish music festival in the country.

Q: What was the original idea of the festival when Ursula Sherman started it?

A: It was as much about building a sense of community as it was about presenting music you wouldn't hear anywhere else. Nobody was presenting Jewish music. The klezmer revival started at the North Berkeley branch of the public library in 1976, with Klezmorim. We were an engine for that revival in that we provided a stage for a lot of those early artists. Now the music, in all its myriad forms, can be heard at the jazz festival, the new JCC (San Francisco) and at Cal Performances. It's more and more of a challenge to find music that people don't know about. We scout internationally. That's our forte.

Q: So what is Jewish music?

A: It's music that reflects the Jewish experience in some way. The lyrics might be Hebrew or Ladino or Yiddish or Judeo-Arabic. We try to present the full range of the music - from new works to liturgical music, music from the Ashkenazi, Sephardic and Mizrahi traditions.

Q: How has the festival changed over the years?

A: We've branched out into new territories, commissioning pieces and developing a school outreach program. In 2006, we commissioned Amy X Neuburg, who'd never done Jewish music. She created a work for voices and electronics inspired by the cookbook that women at Terezin (the Nazi concentration camp outside Prague) put together from memory to keep up morale. This year, we commissioned composer Dan Plonsey. He's creating a multimedia piece called "Dan Plonsey's Bar Mitzvah," which explores what it means to be an adult in today's complicated world. (The work premieres at San Francisco's Contemporary Jewish Museum on July 11, when the festival hosts a free public celebration across the street at Yerba Buena Gardens.)

Q: What's the focus of this year's festival?

A: We're playing with the idea of the sacred and the secular. This year, when everybody seems to be struggling, we all need all the help we can get, whether it's from Jewish and Muslim sacred music and dance, or the Irish and Jewish songs that Susan and Lorin will be doing. Lorin and Frank London of the Klezmatics are singing and teaching niggunim, wordless Hasidic melodies, at a free Shabbos service and concert. Music is a spiritual experience, whatever form it takes. It brings people to a better, healing place.

Q: You've got Klezmer Buenos Aires on the bill. Who are they?

A: Two guys who sound like an orchestra. Marcello plays all the wind instruments. Cesar plays accordion, piano and percussion. They're incredibly creative. They play improvisational music infused with klezmer, tango, Argentine folk music and jazz.

Q: There's a strong cross-cultural aspect to what you do, right?

A: It's very important. Historically, Jews have survived by relating and adapting to the environments that they found themselves in over the centuries. It makes for a wonderful spectrum of possibilities for musicians. Our message is really about using music to bridge cultures.

The Jewish Music Festival: Sat.-March 29. Various East Bay venues, including the JCC East Bay, 1414 Walnut St., Berkeley, and Freight & Salvage Coffeehouse, 2020 Addison St., Berkeley. $20-$30.50. (800) 838-3006. www.jewishmusicfestival.org.