First of two articles on today's teen-agers. Teen-agers today: on the edge of a moral vacuum. Actions of elders, more than rock lyrics, shape outlook of the young

At 9 o'clock on a Thursday evening, 8,000 teen-agers who have forsaken homework and jobs to gather in the Centrum Arena are waiting with cheerful impatience for a little action, a return on their $15 investment. Suddenly a huge banner unfurls: a $100 bill the width of the stage. But right where the staid oval portrait of Benjamin Franklin should be, the spotlight shines on a picture of a scruffy trio: the Beastie Boys, reigning kings of vulgarity and anarchy on the rock-music circuit.

The teen-agers cheer wildly, their faces bobbing in a sea of faded denim and blue Beastie Boys T-shirts ($16). Then the Boys themselves appear. ``Let yourself go,'' they chant, signaling that the tribal ceremony is under way at last.

To wary parents, a rock concert - especially a Beastie Boys concert, with its crude, unmelodic rhythm-and-rap - represents the ultimate clash of values between generations. In this very secular church on this most unhallowed ground, adults fear, outlaw preachers are delivering unholy musical sermons on parental defiance and uncivil disobedience, trying to convert impressionable young congregations to sins - known and unknown.

Yet to many middle-class teen-agers, an evening like this serves as a harmless form of youthful escapism and comic relief, not a corruption of moral sensibilities. That $100 bill on the stage banner, in fact, may come closer to signaling the priorities represented here than all the talk about sex, drugs, and violence coming from the stage.

``You get your own set of values from your parents as you grow up,'' says Mike Giorgio of Worcester, a high school senior attending the concert. ``You don't have to go by the Beastie Boys' values. They're too crazy. It's just entertainment.''

Still, many adults worry that this kind of influence is far from benign. As teen-age suicide, pregnancy, drinking, and drug abuse continue to make headlines, concern about how teens learn values and morals is assuming new urgency.

Interviews with teen-agers, parents, and educators in Florida, California, and Massachusetts reveal a shifting social climate and changing family structures that send mixed signals. And a report by Carnegie Corporation president David A. Hamburg, called ``Preparing for Life: The Critical Transition of Adolescence,'' finds ``an urgent need to improve our capabilities for dealing with adolescent problems.'' Americans, Dr. Hamburg charges, ``are failing to provide avenues for the affirmation of fundamental needs to large numbers of adolescents.'' Those ``fundamental needs'' include reliable relationships, self-esteem, and a sense of belonging.

``I have the feeling we are not making clear to kids what values are,'' says Elizabeth Winship, author of ``Ask Beth,'' a syndicated advice column for teen-agers.

``We are making some kinds of values too clear,'' she continues. ``Television, rock songs, movies, and the media certainly present values about sex that we would not try to teach our kids. Media people and stars and sports heroes have kids out of wedlock and flaunt it. Others are getting arrested for drug abuse and dying of overdoses. These people act as role models. They've been presented to kids as important, successful men and women.

``So it's harder for adults to say, `This is the way you should behave. These are the moral principles we want you to have.'''

To muddy the moral and ethical waters even more, recent insider trading scams on Wall Street and secret arms deals in Washington have turned people like Ivan Boesky and Oliver North into folk heroes of sorts.

Such events send ``indirect messages'' to young people, according to Michael Gonzales, director of Young Community Developers, an employment training program in San Francisco. ``When we have an undisciplined society, as we do now,'' he says, ``that undisciplined behavior gets carried out in schools and other institutions.''

Lee Roy Sullivan, principal of Countryside High School in Clearwater, Fla., expresses similar concern. ``You read every day in the paper about courts and appeals,'' he says. ``People are always trying to beat the system. Rather than looking into the real issue - why did that person kill somebody? - they're always trying to get him out of it. That's a mind set that's beginning to run through the country, and I think kids are going to pick up on it pretty soon too.

``Kids see parents trying to beat the system,'' he continues. ``If we suspend a student, a lot of parents are looking for ways to beat the suspension. They're not spending time on the issue of what the child did wrong and trying to straighten that out.''

Teachers note other small signs of changing attitudes. ``I've caught eight students cheating in the past two weeks,'' says Joanne Anderson, a high school teacher in Edina, Minn. ``It's always gone on, but the percentage of kids cheating is on the rise.''

What's more, she adds, ``They don't feel remorse that they've done something wrong. When I give them a zero for the test, they say, `Can't I take the test over? I can't show my parents a zero.'''

This desire for good grades at any cost is one negative effect of an increasingly competitive society. As teen-agers talk about SAT scores, college applications, careers, and success, words like worry and fear become recurring themes.

``The biggest problem kids face isn't drugs,'' says Paul Artman, a high school senior in Clearwater. ``It's pressure to achieve.''

That pressure, often imposed by parents, also grows out of students' own desire for success and wealth, as symbolized by that giant $100 bill on the Beastie Boys' stage.

``Money is incredibly important,'' says Aydin Keskiner, another Clearwater student, echoing the comments of many teen-agers around the country.

But if students are worried about wealth, so are adults - for different reasons.

``One of the values that concerns me is this terrible emphasis on money in our society,'' says Mrs. Winship. Noting that teen-agers watch an average of 21 hours of television a week, she adds, ``The settings on TV are always in extremely wealthy homes, and people are dressed much better than most families can hope to achieve. It contributes to a greedy atmosphere.''

It can also contribute to a sense of sadness and frustration. ``You look at the Cosby show,'' says Lissette Garcia, a senior in San Francisco. ``Denise and Theo and Vanessa don't have any worries about money. Denise's older sister goes to Princeton. You don't hear her talking about applying for financial aid. They live in a nice, comfortable home. They don't have any worries about money. In real life there are.''

Those real-life worries become acute in low-income neighborhoods.

``A lot of these kids won't ever see a piece of the American pie,' says Keith Grier, recreation director of the inner-city Bodekker Park in San Francisco. ``They want some of what they see on TV. But they know they can never live the life of the Cosby kids. They live in one room. Some of the Asian kids live eight to a room.''

That dual perspective - wealth on the TV screen, poverty at home - produces another problem. ``There's a real lack of role models,'' says Steve Harris-Barton, director of the Mayor's In School Youth Program in San Francisco. ``In poor communities, the person who has everything kids want is the drug dealer. He's the one driving around in big fancy cars.''

For teen-agers today, the world also tends to shrink into a very private sector.

``Our culture is in a swing right now, which I don't think is particularly helpful to the well-being of teen-agers,'' says Tom Cottle, host of the teen-age talk show ``Soapbox.'' ``Our culture has become painfully self-centered. Kids growing up in the '50s and '60s had a much larger sense of a world outside of them that they should attend to, whether it was Korea or Vietnam or civil rights.

``Now it's very hard for teachers to convince them that there is a world they need to attend to. They want to know: `Is it relative to me? Do I need to know this?'

``It's a much more perilous world in many respects - child abuse, the omnipresence of alcohol, cigarettes, drugs, an increase in abduction of children by non-custodial parents. So a certain sense of selfishness comes from just holding on and surviving.''

Survival may, in fact, be the key word. ``Teen-agers are worried about what they're going to do, because they don't have the luxury of not worrying,'' Mr. Gonzales says. ``There are a lot of children who, because of the breakup of families, separations, deaths, have adult responsibilities thrust upon them.''

``You would think they'd be thinking about the future in terms of survival for this country,'' Mr. Sullivan observes. ``I don't hear that among these students as much as I did back in the late '60s and '70s, when social issues were more prevalent. I think these kids just take it for granted there is a future. They don't worry about that. Therefore, they're preparing for the future by staying in school and getting an education. They're more aware of events or things - drugs and alcohol - that might hurt them physically.''

And like their parents before them, teen-agers take their lives more seriously than they let themselves appear to.``No one should get the impression that America's teen-agers are all a bunch of sick, miserable kids,'' says Mr. Cottle. ``They are not. You see millions and millions of fabulous people who, whatever problems they are facing, are leading their lives in very honorable ways. They come from all kinds of families - rich, poor - and they're terrific, marvelous kids.''

Thursday: The role of parents in strengthening values.