Bernstein at seventy.

ONLY SOMEONE who has been on vacation in Antarctica could have failed to realize that Leonard Bernstein was seventy in August. The press, the record companies, and the musical world in general have been turning themselves upside down to find new ways to explain and honor him. A community of promoters, commentators, and concert-goers who formerly baited or begrudgingly admired him are behaving as though a brash showoff had suddenly been transformed into a venerable, white-maned maestro.

While no doubt savoring the birthday tributes and these hard-won accolades, Bernstein must be wearing a slight smile of cynicism, at the very least. How could it be otherwise, when critics who once spent most of their space deriding him as facile and deploring his podium manners now describe his exuberant gestures as the reflection of profound insights and an intense commitment to music? What must go through his mind when those who had long complained that his classical compositions were too popular or his popular music too highbrow now laud his versatility?

His one comment in this anniversary year has been to observe that he is not seventy but "twice 35." But 280 sounds closer to the mark, for he has packed into his seventy years careers diverse and rich enough for four people. A conductor, yes; a pianist, of course; a teacher, certainly. But above all, a composer.

For four decades, Bernstein has dominated what is interesting in America's musical life, and no other individual has so altered the face of music in this land. When he burst into our consciousness on November 14, 1943, at age 25, with a concert with the New York Philharmonic, there was no such thing as an important American conductor. Moreover, there was no such thing as a conductor of any nationality in his twenties or even thirties who was taken seriously.

Conducting was tbe domain of Europeans; someone forty was called a "young conductor." So Bernstein began with two strikes against him. And he was not only a young American conductor, but a young Jewish American conductor. His mentor, Serge Koussevitzky, had solemnly warned him that the name Bernstein would never appear on a poster outside Carnegie Hall and had seriously urged him to switch to Leonard S. Burns.

But Bernstein didn't strike out. Instead, he got the chance of a lifetime that fall day in the midst of World War II. Bruno Walter, the Philharmonic's guest conductor, fell ill and Bernstein replaced him on a few hours' notice, without a rehearsal, for a Sunday-afternoon national broadcast. It was the oldest scenario in the books: Star becomes sick, understudy steps in, understudy becomes an overnight sensation.

His Philharmonic debut was a national event, reported on page one of the New York Times. He started at the top and stayed there. His subsequent triumphs threw open the doors to succeeding generations of American conductors such as Michael Tilson Thomas and James Levine, But Bernstein did more than set an example. He extended a helping hand by showcasing younger colleagues and making the post of assistant conductor of the Philharmonic (which he took over as music director in 1958) truly meaningful and active,

He has also done inestimable service to the cause of American music by using his popularity and position to champion the works of men as diverse as Charles Ives, David Diamond, Ned Rorem, and John Cage. At the same time he has made his own presence as a composer felt through his concert music (first with the Jeremiah Symphony and the ballet Fancy Free) and theater pieces (starting with On the Town).

But two platforms and audiences of thousands were hardly sufficient for the many Bernsteins and all they had to say, and soon he was a familiar figure on television, expounding to millions on everything from what makes jazz jazzy to how Beethoven wrote his Fifth Symphony. What he was dispensing was not simply information, however engagingly presented, but a sense that music is interwoven into the fabric of life and a precious part of our heritage.

Many of the contradictions that have swirled around him have been the creations of writers determined to categorize him but not knowing how. Their repeated attempts to pigeonhole him have reminded me of the old parable about the blind men and the elephant. Asked to describe the beast, one felt the trunk, another the tail, still another a leg. Each had a different answer, but their inadequate reactions could not make the animal less imposing.

Like Gustav Mahler, once the Philharmonic's music director and whom Bernstein venerates and identifies with, he has had a career that is a fascinating series of contradictions. He has had total fame as a performer, but wants to be remembered as a creator. He craves to be accepted and respected by his fellow composers, but has resisted the prevailing tides of serialism and experimentation and sided instead with tonality and melody.

And Bernstein the composer subdivides into at least two different personalities. There is Lenny-the savvy secularist, the composer of "New York" music from On the Town to On the Waterfront. And there is Leonard, the serious sacred composer, who can find equally new and arresting ways to deal with the Jewish Kaddish and the Catholic Mass and break new ground within traditional symphonic and concerto forms.

The common plane for both is faith and the questioning of that faith publicly in order to reaffirm it. It can be faith in an idea, in a person, or in all mankind. Bernstein doesn't think small. And everything he does is the act of a man committed to other men. In a moving essay in a collection of his writings entitled Findings (oh yes, he is also the author of four books) there is a passionate confession by Bernstein the humanist that contributes greatly to our empathy with Bernstein the musician. He writes:

I believe in people. I feel, love and need, and respect people above all else, including the arts, natural scenery, organized piety, or national superstructures. One human figure on the slope of an Alp can make the Alp disappear for me . . . One person fighting for truth can disqualify for me the platitudes of centuries. And one human being who meets with injustice can render invalid the entire system which has dispensed it. . . .

Man cannot have dignity without loving the dignity of his fellow. I believe in the potential of people. I cannot rest passively with those who give up in the name o "human nature" . . . I believe in man's unconscious, the deep spring ftom which comes his power to communicate and love . . . What art can do is extend this communication, magnify it, and carry it to vastly greater numbers of people.

The Bernstein birthday party will continue all season across the land. Here are some of the candles waiting to be lit:

New York: The New York Philharmonic has scheduled 19 Bernstein scores this season at Lincoln Center. Still to come are the suite from the ballet Fancy Free on February 1, 2, 3, and 4, Songfest on February 16, 17, and 18, and the ballet Facsimile on May 25, 26, and 27. The American Symphony performs Trouble in Tahiti and Shivaree at Carnegie Hall on February 19.

Portland, Oregon: The Columbia Symphony will offer one of Bernstein's most recent works, Opening Prayer, on February 3.

Chicago: The Chicago Symphony is planning Symphony No. 1, The Age of Anxiety, on April 27, 28, and 29.

Dallas: The Dallas Lyric Opera will be staging Candide on June 11, 14, 16, and 17.