Musical Strains : Cajun and zydeco are often lumped together, as in this weekend’s Long Beach festival. But back home in Louisiana, there’s a racial dividing line.

Not long ago, a party was held for a group of visitors to Eunice, La., a small bayou town about 45 miles northwest of Lafayette. As the guests chowed down on jambalaya, gumbo and catfish, a group of local musicians representing both the Cajun and zydeco styles that were born in this French-speaking region gathered in a circle on folding chairs. With accordions, fiddles, guitars and their voices, they explored their common musical roots.

The guests enjoyed it tremendously but had no idea that they were witnessing something remarkable. “That’s the first time I’ve ever played with Cajun musicians,” young zydeco accordionist Chris Ardoin remarked after the session.

“That rarely happens in Eunice,” said Ann Allen Savoy, a singer-guitarist and Cajun culture historian who organized the jam along with her husband, accordionist Marc Savoy, and their son Joel.

Though they are branches of the same tree, Cajun and zydeco differ in at least one significant way: Cajun comes from the descendants of French settlers exiled from Nova Scotia 200 years ago (“Cajun” is a corruption of the word “Acadian”); zydeco is the music of the area’s blacks and Creoles.

It’s not uncommon to see the styles represented together on one concert bill, as will be the case at the 11th annual Southern California Cajun & Zydeco Festival on Saturday and Sunday at the Rainbow Lagoon outside the Long Beach Arena.

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Even at such festivals, though, the lineup is divided largely by ethnic lines. This weekend, C.J. Chenier and Nathan & the Zydeco Cha-Chas will have all-black lineups, while Steve Riley & the Mamou Playboys and D.L. Menard are all-white acts. The only integrated band on the bill is, in fact, from outside Louisiana: Danny Poullard & the California Cajun Orchestra.

“In Louisiana I have yet to see mixed bands,” says Poullard, an accordion-playing Creole native of Eunice who has lived in the San Francisco Bay Area for 40 years. “It’s still a race thing down there.”

The division in rural Louisiana is even more dramatic among the fans. “People keep to their own,” Poullard says. “Whites that go to the zydeco clubs there tend to be from out of state.”

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Barry Ancelet, professor of French and folklore at the University of Southwestern Louisiana in Lafayette and a leading historian of Cajun and Creole culture, agrees that the segregation persists. But he feels that, at least among the musicians, the ongoing and even widening separation is a matter of aesthetics, not race.

It wasn’t always like this. Creole accordion pioneer Amadee Ardoin and Cajun fiddler Dennis McGee were a noted team in the ‘20s and ‘30s--when, as Ancelet points out, Jim Crow laws were the order of the day in Louisiana. In the ‘60s, when racial tensions were stirred by the burgeoning civil rights movement, Cajun fiddler Dewey Balfa made a record with zydeco’s Rockin’ Dopsie, and Marc Savoy and the late zydeco “king” Clifton Chenier (C.J.’s father) often played together.

“Both Cajun and zydeco were born because African and European French cultures met on neutral ground in the New World,” Ancelet says. “It’s the same marriage that produced jazz, and later rock ‘n’ roll.”

But in recent years, while Cajun music has undergone a revival of its traditional French elements, zydeco has moved in the opposite direction.

“You have a situation where the hottest zydeco song of a few years ago was called ‘Going to McDonald’s’ [by accordion player Keith Frank],” Ancelet points out. “I’m sorry, but that’s an impoverished culture. Zydeco has drifted from its origins to the point where Cajun musicians would have trouble playing those songs. And zydeco musicians are less than interested in playing the old stuff.”

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Nathan Williams, of Nathan & the Zydeco Cha-Chas, confirms that. He made an album in 1995, “Creole Crossroads,” with Cajun fiddler Michael Doucet, but Williams says he isn’t keen about mixing the styles on a regular basis.

“They’re just different because of the beat and different tempos,” says Williams, 34.

His upcoming album--”I’m a Zydeco Hog,” recorded live at the Rock ‘n’ Bowl bowling alley / music club in New Orleans--is a case in point. Its funky grooves and bluesy jams are far removed from the rural origins of the music.

“It’s not that I’m changing the tradition,” Williams says. “I’m focusing on the future, moving forward, keeping the music alive and making it different.”

The separation of the styles frustrates Franklin Zawacki, who produces the Long Beach festival along with ones in San Francisco and Rhode Island.

“In Rhode Island, we’d mix the bands on stage, and I had no idea that it wasn’t done back home,” Zawacki says. “Over the years we’d hear it from the musicians, Creole musicians the most, that they were uncomfortable with this.”

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He might be in for a pleasant surprise this weekend, though.

“I think it’s a great idea if we have a jam [at the Long Beach festival],” says Steve Riley. “I hadn’t really thought about it, but I’m gonna try to figure out something we can do.

“There are lots of festivals and clubs where I’m on a bill with C.J. Chenier and I’ll get on stage and play guitar with him, or he’ll play sax with us,” says Riley, 28. “And [zydeco musician] Geno Delafose and I went to school together and play together all the time. It happens. Certain musicians are open to it, certain ones aren’t.”

* The 11th annual Southern California Cajun & Zydeco Festival takes place Saturday and Sunday from 11 a.m. to 7 p.m. at the Rainbow Lagoon, 300 E. Ocean Blvd., Long Beach (the music starts at noon). $22; $15 for students and seniors; $5 for children 10 to 16, free for children under 10. (562) 427-3713.