Down at the Smithsonian's Festival of American Folklife, the Cajun music, food and exhibits are a predictable success. Of course, it's the music that erases cultural boundaries the quickest and easiest. If you have any doubts, just check out the dance party thrown by the Cajun band File each day of the festival at 5:30 p.m. Before you can count off a waltz, the couples are swirling and swaying to the lively, exotic strains of fiddle and accordian.

Composed of Ward Lormand, Faren Serrette, Ray Brassieur, Kevin Shearin and Peter Stevens, File will also play at Friendship Station tonight and Saturday with blues man John Little John. The band's dedication to a traditional French repertoire is part of a broad cultural renaissance, now more than two decades old, aimed at the preservation and revitalization of the traditions of French-speaking south Louisiana. File's goal is not simply to entertain music fans around the world, but to keep alive what is uniquely theirs.

"We formed about a year and a half ago," says Brassieur. "Three of us had been in another band, Cous Cous, that had been playing traditional French music, and File has kept that concept. We love the music. We feel it helps preserve our heritage and spread the word to people in our own community who haven't realized they are Cajuns yet."

For the most part File's music is extremely traditional, and the group sings in French. But the repertoire also reflects those American styles that have influenced Cajun music.

"We play mostly two-steps and waltzes," Brassieur says, "but we also do a few early rock 'n' roll numbers that were common in south Louisiana. We do some bluesy things, but they are blues that go way back in south Louisiana. Some of our music is more recent, like the country stuff, but most of our melodies are very old and definitely European. Our oldest song is probably 'Le Chanson de Mardi Gras,' which folklorists have traced back to the Middle Ages, and oddly enough, England. That's the oldest one I know. Many of our songs have obscure origins."

In their short history, File has played a number of Louisiana festivals, including the Cajun Music Festival, the Beaux Bridge Crawfish Festival, the World's Fair and the New Orleans Jazz and Heritage Festival. They've also played in Canada, opened for Loretta Lynn, and have now brought their exuberant dance music to Washington, which, Brassieur notes, has a somewhat analytical audience.

"The crowd reaction has been stimulating," he laughs. "But one thing I've noticed is that some of the people who've come to see us here are quite serious about the music and want to categorize it. One question that always comes up is, 'What is the difference between Cajun and zydeco music?' You see, we play some zydeco too. The other day J.C. Gallow, who plays rub board with the St. Landry Playboys, joined us on stage. Anyway, this guy walks up to the stage, looks at us, looks at J.C., who is a black man, and he says, 'What's the difference between Cajun and zydeco?' Our drummer answered, 'Well, one starts with a "c" and the other with a "z." ' "

Attempts to pin Cajun culture down are bound to meet with some failure, simply because the traditions are as alive and independent as the Cajun people themselves. Two of the band's members have played interesting roles in the preservation of their culture -- Brassieur, who is an anthropologist as well as a guitarist, has worked as curator of the Acadian House Museum in St. Martinville, and Feren Serrette, who plays fiddle, is currently running the Cajun boat building exhibit at the Festival of American Folklife.

"Faren and his dad are traditional boat builders," Brassieur explains. "Boat building has always been important in Louisiana because of all the waterways. It has been a well-developed occupation and skill. Faren and his dad built a boat at the World's Fair last year, and the plans for the boat came entirely from the memory of Mr. Serrette. Faren's doing a similar project here. New materials are taking the place of wood, and one day it may be impossible to find wooden boats. We're trying to keep the skills required to build wooden boats alive."

Yet there is the question of whether broader exposure can threaten this distinctive cultural enclave.

"There is a danger," Brassieur says, "but it's one that's been there throughout the 20th century. There have been many outside influences and pressures that have worked against our cultural integrity, like the media and TV, which are all in English. But we've already been through that quite a bit, and we're still here."