There were three rock 'n' roll stars in the light plane that crashed in an Iowa cornfield during a snowstorm in early February of 1959. Remember the day the music died?

Buddy Holly's songs live on mostly for better, sometimes for worse -- one's just been picked up by Buick for a commercial -- and his story's already been told on film. Maybe someday the Big Bopper will warrant a cinematic second look, but right now, almost three decades later, it's Ritchie Valens' turn.

"La Bamba," which opened Friday, is writer-director Luis Valdez's poignant and passionate portrayal of Valens' all-too-brief moment in the sun. The film, shot in various California locations, including Valens' home town of Pacoima, follows his rise from laborer in the orchards of the San Fernando Valley to guitarist in a Pacoima garage band, from basement recording studio to top of the record charts. Valens' career lasted all of eight months; he was 17 when the plane went down.

Valens is one of America's least known stars -- he wasn't even listed in Lillian Roxon's "Rock Encyclopedia," the first rock reference book. Uncovering his story, as Valdez soon discovered, required a bit of detective work, including tracking down the surviving members of his family to get at the truth of his brief life.

"The one thing that comes across is this kid was innocent in all senses of the word," says Valdez. "He was growing up, he had this barrage of attention and he was just learning about himself. In one of the last photographs, taken the night before he died, you can see a maturity in his face."

Despite his youth, Valens wrote and performed three chart hits in less than six months -- "Come On, Let's Go," "Donna" and the exuberant tune that gives the film its name -- an achievement unmatched until the arrival of the Beatles. More importantly, he was the first Mexican American to break into the rock charts of the '50s.

Based on a Mexican folk song Valens had grown up with, "La Bamba" was the first rock hit imbued with a Latin sound and sung in Spanish. Yet few people that realized Ritchie Valens, whose real name was Richard Valenzuela, was Chicano. His manager had changed his name, and, ironically, Valens was at first reluctant to record a song in Spanish.

Growing up in California, Luis Valdez suspected "La Bamba" had Mexican roots but even he wasn't sure its singer did until much later. Valens would remain a barrio secret for almost 30 years, waiting for someone to reveal him.

"Ritchie Valens made it on raw talent and honest ambition," says Valdez, a playwright and director who has been working for more than two decades to change the way America perceives its Hispanic citizens. For him "La Bamba" is not simply a story of ethnic triumph: Ritchie Valens' dream of being a rock 'n' roll star is just one more expression of the American dream, where assimilation and integration can be as important as success.

The ethnic triumph is important, of course. For years, America's minorities have been going to the movies to watch Anglo kids coming of age. With "La Bamba," the tables are turned.

"America still lives with images of the '40s and '50s," says Valdez's brother, actor and associate producer Daniel Valdez, "yet there's been a tremendous cultural evolution that's taken place and nobody knows." The brothers were in town recently for special "La Bamba" screenings at the American Film Institute.

"The star of 'La Bamba' is the story," Luis Valdez says. "For the first time a character actually makes it, and he has all these strong family values. He's not a cutthroat, he's a gentleman, he has dreams like anybody else."

"Really, the attraction of Ritchie Valens is that the dude made it, he got to the top," Valdez adds. "We're all born struggling out of the same mass of placenta and blood, mewling and mauling and clawing in order to get someplace. Getting someplace takes a fight, and it's the same fight for everybody. That's all we're saying. When the green light says come on ... let's go."

Not that "La Bamba" is a one-dimensional, single-story-line film. Yes, it's about a young man's rise to fame, but it's also about puppy love between a Hispanic boy and an Anglo girl, a Hispanic stage mother, and an epic struggle between a good half-brother (Ritchie, played by Lou Diamond Phillips) and a bad one (Bob Morales, played by Esai Morales, who is of no relation).

"We did try and make Ritchie as human as possible," says Daniel Valdez, who tracked down the Valenzuela family. "People were very protective. His family went and hid after he died. They didn't want to deal with reporters or anyone, so they just pulled up roots from Pacoima and moved. And nobody knew, or would tell, where."

Eventually, Daniel Valdez found them in Watsonville, Calif., just 16 miles from San Juan Bautista and El Teatro Campesino, the dynamic Hispanic theater founded by his brother. All of the family members old enough to have known Ritchie contributed, but the key was Morales, portrayed in the film as a hard-drinking, fun-loving, trouble-causing type. In the swirl of sibling rivalry and loyalty, Luis Valdez found the crucial center for his film.

"When you first run into the material, that's what you have: Ritchie was a nice kid, he never swore, he never did anything bad, he made three records and then he died," says Valdez. "In talking to Bob, getting a lot of his jealousies, his feelings of love, I recognized that it was the stuff that I needed. I had found a real raw nerve."

'A Farm Labor Child' Originally, Luis Valdez was slated only to write the "La Bamba" script, but he ended up behind the camera when the original director, Taylor Hackford, became the film's executive producer. The change was "an organic evolution," Valdez says. "I usually don't write what I can't direct, and when Taylor read the screenplay, he saw it as a personal vision, since there were so many elements in it that had come from my own direct experience."

Valdez's move to the top was less sudden than Valens', but so much of "La Bamba" echoes the director's own life that its promotional line, "An American Success Story," seems to apply as much to filmmaker as to subject.

One of 10 children, Valdez was born in 1940, just a few years before Valens. He grew up in the San Joaquin Valley, where he would come to know both the good and the hard life early on.

"We had been farm workers, following the crops {grapes and cotton}," explains Valdez, who is short and stocky, and speaks in a rich, resonant voice. "When I was very young, I was severely scalded and almost died; the local hospital refused to admit me because I was a 'farm labor' child and they didn't do those things in those days. So for six months I slept on my mother's stomach while the skin on my back came back into place."

Then came Dec. 7, 1941, and the Japanese attack on Pearl Harbor. Soon after, California's many Japanese American farmers were sent to detention camps. "They were tremendously effective, had these small, productive farms," Valdez recalls. "When the Army rounded them up, all these farms were left idle and vacant, so the Army turned around and offered them to the Mexican farm workers, one of which was my dad. So from 1942 until 1946, we had a ranch, we had land, we had money; I grew up with all that.

"When the {Anglo} veterans came back and didn't need the Mexicans to run the ranches anymore," Valdez says, "we conveniently ran out of loans, the market shriveled up, it was a bad winter. So we lost the farm and hit the road again. In the first years of my life I experienced a sense of prosperity and equality that I longed for, then suddenly I was wondering what we were doing living like slaves. When I finally found out what had happened, how the Japanese had been dispossessed, I felt a real sense of guilt."

Valdez says he was politicized "by my early experience in the field, picking cotton for such low wages {$3 a day}, touring the migrant labor camps, living in those miserable conditions, going into town and being looked at strangely -- 'here come the Mexicans.' And this in a place where I'd been born. What the hell was going on?"

As for his theatrical vocation, he says a single grade school incident provided the spark.

One day, the family truck broke down, and while it was being fixed, Valdez started attending school nearby. There were still shortages, including paper bags, so he treasured the one he carried his lunches in.

"I used to take care of my bag, fold it, keep the grease spots off it," he says. "Then one day it was gone at the end of the day. My teacher saw me looking for it, pulled me over and there it was, all pulled apart, floating in a bucket of water next to a clay mask. I saw the connection and I was amazed. I learned about papier-ma~che' in an instant."

The mask was for a play. He auditioned, got the part, "and got a costume, which was better than my own clothes. The week before, the truck was fixed and we split, so I was never actually in the play. But I was hooked on theater from then on."

Years later, at San Jose State College, Valdez started out as a math and physics major, switched to English and then went on to creative writing ("I was afraid I might end up being an English teacher"). His first play, "The Theft," took first place in a San Jose Theater Guild contest, the prize being a performance in a park. "I no longer have a copy of it but it had to do with Christ and a beatnik, the kind of thing a 19-year-old might write," Valdez says.

He continued his studies with the late Harold Crane. "I'd write, he'd correct," Valdez recalls, and when he had finished his next play, "The Shrunken Head of Pancho Villa," the professor suggested he direct it himself. "He said, 'It's your vision.' And so I became a director."

There was an early-'60s stint with the politically active San Francisco Mime Troupe, with frequent performances in the city's parks -- valuable experience for Valdez's next venture, performances in farm fields.

"In the summer of 1965, I heard about a union starting in Delano," Valdez says, near where he'd been born and raised. "At one time, I thought Delano was the sump hole of the universe. As it turned out, it was mecca. I ended up going back and confronting all these ogres from my past -- the labor contractors and the ugliness of the camps. Only by this time I had theater as my weapon.

"And I used it."

That same year Valdez organized El Teatro Campesino (The Farmworkers Theater), drawing his actors and actresses from the grape fields and the picket lines, performing on the backs of flatbed trucks. With Brecht, commedia dell'arte and such socially conscious '30s theater groups as The Living Newspaper as models, Campesino offered raw, simplistic agitprop actos, or skits, centered around la huelga (the strike). Soon, the troupe started traveling around the country, raising funds for and consciousness about the struggle of the United Farm Workers. Twenty years ago, it performed in Washington, at Howard University and in the Senate Courtyard for the Senate Committee on Agriculture and Labor. A year later, it would receive an off-Broadway Obie award.

In the late '60s and early '70s, El Teatro Campesino planted the seeds for many Chicano theatrical groups -- at one point there were more than 100, though only a handful remain. Still, by 1971 it was time for a change. Valdez moved the company to San Juan Bautista, a small, rural town 30 miles south of Fresno.

"We were tired," he explains. "Not of working in theater, but of the screaming and shouting, of being jailed and beaten. And we were tired of the infighting in the movement. We needed a period of introspection."

'Two Great Big Melting Pots' Over the years, El Teatro Campesino has won three Los Angeles Drama Critics Circle Awards -- including one for "Zoot Suit," Luis Valdez's best known work before "La Bamba."

"Zoot Suit" was a mix of musical theater, courtroom drama and pop mythology centered on pachucos, the style-conscious Mexican American street youth of the 1940s. The play was based on the "Sleepy Lagoon" murder case, in which 600 Los Angeles "zoot suiters" -- identified by their voluminous jackets, pegged pantaloons and floor-length key chains -- were rounded up for a single murder. Twelve were sentenced to life in prison, though they were freed on appeal 18 months later.

The roundup and the trial were part of a blatant harassment of Chicano youth during World War II, and Valdez captured not only the cultural dualities and racism of the time, but the mythic stature and bitter alienation of the pachuco, chillingly embodied as a kind of one-person Greek chorus by Edward James Olmos (who would later win an Emmy for his work on "Miami Vice"). Daniel Valdez portrayed Henry Reyna, the key accused.

"Zoot Suit" was a hit in Los Angeles, where it ran for almost a year. But it didn't translate to New York, though its brief run allowed Valdez to become the first Chicano to have a play produced on Broadway.

A worse fate befell the film version. Shot in 13 days on a budget of $3 million, it was a fully cinematized version of the play, expanded from the stark theatrical presentation. Although its limitations are apparent, "Zoot Suit" is a powerful film; unfortunately, hardly anyone has ever seen it. After some disastrous sneaks, it was shelved and has not even made it onto video (a situation that should be changed by the success of "La Bamba"). "It's a source of tremendous frustration," Valdez admits. "We're waiting it out, like good Indians."

Since "Zoot Suit" (which was not a "realistic" film, the director says, but "had stylistic sublayers of reality"), Luis Valdez's work has become increasingly realistic -- and some might even call it mainstream. His most recent play, "I Don't Have to Show You No Stinking Badges" (a famous line from John Huston's film version of "The Treasure of the Sierra Madre"), is about an Archie Bunker-like family: Buddy and Connie Villa, who have established a comfortable suburban life style through a Hollywood career full of bit roles as ethnic Hollywood stereotypes, and Sonny, who drops out of Harvard Law School aiming to become a Hollywood star.

American society is well satirized in the play, from the crass ambitions of the upwardly mobile to the defensive crouch assumed by those who actually make it up the ladder a few rungs (the elder Villas at one point complain about the new Asian influx). And there are some wicked spins on ethnic stereotypes.

At the same time, there's a serious subtext about individuals' determination to pursue the American dream and to participate in its rewards. Even the title is double-edged, reflecting not only Hollywood's generally crude and demeaning portrayals of Hispanics, but also their refusal to keep proving themselves to Anglos. The play ran in Los Angeles for nine months, is still in production in other California cities and has been optioned for a possible network sitcom.

Though its humor is both ethnic and universal, some Hispanic critics have accused Valdez of abandoning his roots, pointing out that while much of his previous work has had bilingual dialogue, "Badges" is entirely in English. The least kind have called Valdez a "Tio Taco," a Hispanic variation on Uncle Tom.

In truth, Valdez no longer defines himself as a Chicano playwright, much less one who must lean on the Spanish tongue. "These days, really, I'm using the word 'American,' and if other Americans can look at me and say, yeah you look like an American, I think something might have changed ...

"A lot of Hispanics don't speak Spanish," he says -- Ritchie Valens among them. "We are talking about something deeper than language here. What happened to the Yiddish theater in America? It became part of the American mainstream and the American theater gained as a result. What happened to all the African tongues that black people speak? They went into their culture in other ways. Human memory persists. There's something about culture that lives through generations, and it's the same way with Hispanics."

Speaking of language, the Valdez brothers point out that there's no consensus about what the millions of Americans with roots like theirs should be called. Chicano (meaning an American of Mexican descent) is a relatively well-defined label, but what about the broader group of citizens with Latin backgrounds? Are they Hispanic? Latino? Condemned to some kind of permanent hyphenated state?

"We're into a transitional thing," Luis Valdez says. "If you ask among Latinos, they prefer Latinos; it sort of speaks for us. Hispanic is something that's really more American, it's in English. We don't mind using it. It's kind of general pablum, like Anglo."

"We're not from Hispania," Daniel Valdez laughs. "Some people are calling Lou {Diamond Phillips} a 'new-age ethnic, a neo-Mayan.' "

"The important point is that the word Hispanic refers to another melting pot," says Luis Valdez. "There's no such thing as the Hispanic race. You're talking about mixture here, anywhere from Ghanese black African people to mulattoes to blue-eyed, blond-haired Spanish types to Indian Joe -- that's me.

"We're talking two great big melting pots looking at each other. There's no purity in it, only mixture. Everybody's a mongrel."

Two melting pots there may be, but you wouldn't know it from the images on American screens. Which is why films like "La Bamba" seem so important to Luis Valdez.

"Our attempt now is to reach as large an audience as possible," he says. "And what's wrong with that? The mass media is something that continues to influence all of us, and no amount of purity is going to save anybody. We're all infected by it, it's all-pervasive, so you make a choice to either participate or not to participate.

"Tune in, turn on and drop out may have made sense back in '65; it makes no sense to me in 1987. I want to participate, I want to speak out in ways that more and more people can understand. What we're doing is emphasizing certain things that seem real to us, that concept of America that allows for differences, for multicultural diversity. We think that's a good idea."