Wynton Marsalis, the premier jazz figure of his time, leans against his black baby grand, lovingly explaining the life and legacy of Louis Armstrong to a Brazilian TV crew. The interview was supposed to have ended half an hour ago, but Marsalis waves off his publicist. He is hard into Teacher Wynton mode now, tracing Armstrong year by year from New Orleans to a Chicago ballroom.

Marsalis speaks softly, as if to an eager child, his sentences brimming with awe as he honors the great trumpeter's "continuous invention," his "great genius," his "heroic character."

The Brazilians nod silently. Then Marsalis shifts into Agitator Wynton mode:

"Some people called Louis Armstrong an Uncle Tom. But he took a very heroic stand on the school integration controversy in Little Rock in 1954. All those jazz hipsters didn't speak out and they didn't come to his defense. Louis Armstrong was a revolutionary in the context of his time."

At the ripe old age of 33, Marsalis -- having long since established himself as an extraordinary jazz-classical crossover success and role model for a new generation of jazzmen -- is tired of his tag as the unbending traditionalist.

A decade ago, the trumpeter faced down the fakers of fusion and restored classy comportment and elegant dress to the jazz stand. He reset history's clock to the bop era, heaving overboard the excesses of the '60s and the cheap simplicities of the '70s. He made it cool to be a jazz player once more.

For that achievement, he now yearns to be seen as he portrays Armstrong, as a revolutionary in the context of his time.

But Marsalis's definition of revolutionary is novel: His revolt is more of a restoration. Preserver of the past, arbiter of style, jazz's disciplinarian -- this is Marsalis's "revolutionary" response to the shallowness, sloth and ineptitude of jazz in the 1970s. He believes he has restored the primacy of the trained musician over the shaggy dudes in T-shirts who built careers on a repertoire of three chords and a fuzz pedal.

"This has been one of the biggest transitions ever in the music," Marsalis says. "People went from not playing to playing."

Marsalis -- who appears at the Kennedy Center Concert Hall Wednesday with a quartet including local pianist Loston Harris -- is likely to blossom this year into the Leonard Bernstein of jazz, bringing the music to a vast audience with a public TV series and a National Public Radio program. He has disbanded his septet to spend more time composing, visiting schools and studying the music of foreign cultures.

But despite his success, Marsalis can seem bitter and defensive. His leadership of the Jazz at Lincoln Center concert series has become a lightning rod for racial politics, and Marsalis is given to angry denunciations of "the critics" and unsolicited defenses of his actions.

Musically, he is in perpetual motion. In the next weeks, his latest release will reach out to an even broader audience. "Joe Cool's Blues," a collection of jazz numbers written for the "Peanuts" TV shows, features Marsalis's septet and his father's group, the Ellis Marsalis Trio. {For a review, see Pop Recordings, Page G8.} It is light, bright, bouncy stuff that will fit neatly into the newly popular "smooth jazz" formats popping up on the FM band in many cities.

"Just another record, man," Marsalis says. "We do so many of them. I did this one because I always liked Charlie Brown. They would always be swinging."

Marsalis pads around his Manhattan apartment, 29 stories over Lincoln Center and the Hudson River. He picks up a cornet, scribbles a change on the score of his new string quartet, ushers a visitor into his bedroom, where five-foot-tall loudspeakers loom over the bed.

He's grown a tad chunky of late, and he looks utterly relaxed, barefoot and smiling in burgundy jeans and a faded denim shirt. But he is impatient: Shown two prospective covers for "Joe Cool's Blues," he tells an aide, "Whatever. I don't care. I just want them to come out. Eleven CDs waiting to come out."

He moves, much faster than the record industry. Around his apartment, around the country, around the music. Make product, get it on the market and get on to the next thing. He has an evangelical zeal about jazz. He travels the country checking out high school and college talent, looking for kids who have the chops and the discipline to join him on his high road.

This wins him extraordinary plaudits from his disciples. Marcus Roberts, the pianist who is one of Marsalis's most accomplished discoveries, provides a sense of the worshipful atmosphere in which Marsalis creates. In the notes to Marsalis's devotional jazz suite, "In This House on This Morning," Roberts writes, "You see, Marsalis was sent here on a mission."

It is hard to escape the air of sanctimony and righteousness that surrounds Marsalis and his acolytes. Critic Stanley Crouch, Marsalis's intellectual mentor for 16 years, speaks of the trumpeter's "purity," of his triumph in restoring quality and discipline in "a period in which the decadent and the inept are celebrated as though the loss of purity into darkness is an achievement."

But there are also young musicians who sneeringly refer to Marsalis as "Mr. Wisdom." And there are music critics such as Ron Wynn, who calls Marsalis king of "jazz's flat-Earth society," or Tom Moon, who calls the trumpeter "the roadblock" in the music's evolution. Many jazz writers have argued for years that despite his technical proficiency and knack for inspiring young players, Marsalis as musician just doesn't swing. Somehow, they say, his playing and his compositions lack precisely the emotional kick that Marsalis so proudly touts in his new coffee-table book, "Sweet Swing Blues on the Road."

Those charges have nagged at Marsalis, leading him to dismiss most writers with disdain. But the most painful dispute of all has been the ugly row that has divided the New York jazz scene for months: Marsalis, critics say, practices Crow Jim -- reverse racism -- at Lincoln Center.

"For years, jazz was nonracial," says James Lincoln Collier, a New York jazz writer whose book "Jazz: The American Theme Song" argues that whites played a larger role in the creation of jazz than is now commonly assumed. "Then along came militant blacks who created this racial polarization."

Collier's anti-Marsalis argument starts with race and goes on to maintain that Marsalis is neither an innovator nor even a successful recruiter of new talent.

"Wynton was a star as a child, and he got an ego," says Collier, who is white. "So the Lincoln Center program is not about jazz, it's about Wynton Marsalis. He thinks he's a jazz god like Armstrong. And he has an agenda: He uses the same people over and over in performance because they are black and they are his friends."

Marsalis and Crouch bemoan the attention the race debate has received.

"Is this going to be another article about why don't they bring {pianist} Cecil Taylor up to Lincoln Center?' " Crouch asks. "Because we can stop right here. Most of the people who tell Lincoln Center and Wynton Marsalis what to do don't know half the music he does."

Crouch, a former jazz drummer who is writing a biography of Charlie Parker, met Marsalis when the trumpeter was 17. The critic began the education of Wynton with reading and listening assignments. These days, Crouch writes Marsalis's liner notes, works with him on the Lincoln Center programming and serves as the musician's ambassador to the intellectual community.

"When I met him, we didn't have an intellectual kinship because he didn't know that much," Crouch says. "But he had an extraordinary confidence and an astonishing ability to play his instrument. I loaned him some records so he could see what Ornette Coleman was all about. He's a formidable reader, so I bought him a copy of {Thomas Mann's} Joseph and His Brothers.' He's probably the only jazz musician who ever read it all the way through."

Crouch champions his protege as a beacon in a contemporary society that adulates strutting mediocrity and tempts musicians with fast life and low standards. Jazz's rewards seem subtle and abstract compared to the celebrity and cash that pop success dangles before impressionable musicians.

"After Miles Davis sold out, you had a remarkable ripple effect. All kinds of people who really could play stopped playing and tried to grease their way into the aesthetic posterior of the rock world," Crouch says.

Crouch believes criticism of Marsalis stems from his refusal to conform to mass media expectations of black artists: "Media tells you to dress in funny clothes, strut on stage, curse and pull your genitalia if you're a man, and never develop into a serious musician. The convention is vulgarity. Wynton Marsalis is rebellious: He dresses properly and speaks intelligently. He will not be daunted by the tyranny of the majority."

Both Marsalis and Crouch assert that music critics are wildly biased against Marsalis, panning compositions they would have praised if only the composer were one of the favored avant-garde jazz figures, such as Henry Threadgill or Lester Bowie.

During a raucous debate staged at Lincoln Center last year, Marsalis trounced Collier, winning over the crowd by belittling his critic's arguments and trumpeting statistics showing that the concert series has included 178 black musicians, 98 whites and 41 Hispanics. But critics counter that the series steers clear of white headliners or tributes to white players or composers.

"People know what this is all about," Marsalis says, his voice rising above its customary gentility. "People know what we've had to face from a certain segment of the white population -- and from certain blacks too. We have a whole history of antagonism, of shame. The truth is, I don't look at a white musician as someone different from me.

"If it means I'm going to be called racist because I hire the musicians who are best, that's okay. I didn't care when I had to fight rednecks in high school. And no amount of vituperative, incorrect commentary is going to change me now. The music is much greater than me and much greater than them."

The race and jazz debate -- already the subject of two books and countless acres of newsprint -- degenerates quickly into vicious name-calling and pointless head-counting. Marsalis called Collier "a poseur . . . a viper in the bosom of blues and swing." Of his critics in general, Marsalis has said: "These men's backsides will never have these brown lips to graze them."

Beneath the debate lie questions about Marsalis's approach to jazz as an expression of the black experience in America, and about the music's status as an art -- growing or dying, popular or elite, fit for the museum, the college campus or the nightclub?

Jazz is far from dead, Marsalis says, but it has reached a level of maturity where its basic forms are set. "It can't change dramatically," he says. "You don't grow now like you did when you were 6. You evolve, but slowly."

If that hardly sounds like the revolutionary Marsalis claims to be, Crouch is standing by with the exegesis. "The question is whether art is going to be looked at like airplanes or automobiles," Crouch says. "The airplane that Orville and Wilbur Wright put up at Kitty Hawk was inferior to the jets of today. But the invincible facts of aerodynamics are the same.

"Now, the music of King Oliver is not inferior to the music of today. There's no painter greater than Goya. Art does not progress. Wynton Marsalis makes better recordings than King Oliver because technology has progressed. But the art is no better. For art to be better, people would have to be better. Are people improved? No."

That bedrock conservatism -- belief in a jazz canon, skepticism about the idea of progress -- is far more than an intellectual abstraction to Crouch and Marsalis. It drives the way they program at Lincoln Center. It defines the music Marsalis writes such as (a string quartet premiering in May in New York). And it defines his recordings -- a new classical album is coming, in which Marsalis repeats performances of three concertos he recorded more than a decade ago. (He says he hardly ever plays classical music, practicing only for a couple of weeks before he records. He does the occasional classical album because "I just like to play. I like the sound of piccolo trumpet in a cathedral. Stentorian, man.")

Marsalis hardly carries himself as a revolutionary. Look at the closed-eyes, head-bowed, prayerful pose he takes on the cover of "In This House on This Morning." Listen to the formal, almost rigid content of that musical rendering of the black church experience. Marsalis seems constricted by his role as the serious savior of the jazz tradition.

When Marsalis speaks with his horn, he grows and experiments (within the limits he has set as a mainstream player). His influence on the scene is enormous.

But the Marsalis who speaks with words tends to muddy the waters.

Collier and other critics charge that Marsalis's influence has failed to expand the music's audience. Marsalis denies this, offering anecdotal evidence of sold-out concerts and club dates. But record sales figures show that jazz's 4 percent share of the music market is shrinking toward 3 percent -- a small, possibly insignificant change, but certainly no boom.

Marsalis says he does not seek to achieve the impossible -- jazz as pop music. Rather, he simply wants to expose as many people as possible to jazz and let them experience its lure. He claims not to care whether those people are young or old, black or white -- yet he insists that jazz is a "Negro music." He dismisses the notion that his Lincoln Center and PBS ventures are evidence of the music's elitist appeal. Marsalis spends many weeks each year traveling far and wide, offering his talent in the most neglected neighborhoods, hoping that jazz will enrich and inspire young people, and especially young blacks. "Lincoln Center is buildings, man," he says. "There is no high culture in America. Anybody goes to anything. Some people pay $80 to go hear people holler and scream."

Whatever the composition of the audience, Crouch says, the music is a black form of expression. "Everybody who plays jazz is involved in something Negroid," Crouch says. "That is style, not genetics. But great Negro artists are not representative of black America. Race has nothing to do with it; this whole topic is ludicrous. The overwhelming majority of black Americans like garbage music just like everyone else."

Much as Marsalis's critics may hark back to a day when jazz was "nonracial," no such day existed. Jazz, the most American of arts, could never have been nonracial -- the American dilemma of race cannot be held at bay.

"Jazz critics are more concerned with race than with music," Marsalis says, more exasperated than angry. "Beethoven was Beethoven. He wasn't the German. Whereas with jazz, you talk right away about the musician's neighborhood and his attitude toward race. Well, that's not going to go anywhere. We are tied to each other and we have to try to deal with each other. Believe me, the Caucasian and the American Negro are forever wed. " CAPTION: Wynton Marsalis.