Always Crescendo : Leonard Bernstein’s meteoric rise seemed to last all his life--but so did his sense of being torn: Was he a composer or a performer? Highbrow or popular? Gay or straight? : LEONARD BERNSTEIN, <i> By Humphrey Burton (Doubleday: $25, 581 pp.)</i>

It was a marvelous life. And Leonard Bernstein, of course, knew it. As a young conductor, he once urged on a student orchestra, telling the players in rehearsal: “Give it all you’ve got and then crescendo.” Having done just that, himself, in the most celebrated musical career in America for the next 45 years, he said, on his 70th birthday: “I feel that I have lived five lives or so already.” A few days before he died at age 72, his body no longer able to beat the odds against such an accelerated lifestyle, he began his own elegy: “Cut down in the prime of his youth.” He meant it.

We all knew Lenny well. He lived in public. He made music accessible. He was both a showman and a man of self-absorbed reflection. He analyzed himself endlessly to friends, to journalists, in his music, in his writings. He talked and talked, and taught and taught, to television audiences, to concert audiences, to students. He partied and partied, living to the hilt the life of a major celebrity. He entertained presidents, kings and emperors; he seduced young writers and musicians. People talked about him. He was biographied, in sober German manner, in American fanzine style and, in a controversial 1987 psychobiography by Joan Peyser, in sensationalistic style. Memoirs have been written by family and friends over the years.

But we are going to get to know him a lot better. There are at the moment, 3 1/2 years after his death, 21 books about Bernstein currently in progress. All will have to contend, however, with Humphrey Burton’s biography. Burton, a British television producer who made concert videos of Bernstein for 20 years, was allowed by the Bernstein heirs exclusive access to the Bernstein archives, including his correspondence. The result is the most detailed report, by far, of Bernstein’s life.

In a disclaimer, Burton says that despite the invaluable support from the Bernstein family he wrote only what he wanted. That’s probably true. The biography does not seemed whitewashed. But Burton is a close friend of the family--Bernstein played organ at his wedding--and could clearly be trusted. Not a practiced writer, Burton has very little voice in the book. The writing is dispassionate, flat, seldom judgmental. But the style is also a relief, with none of the motherly clucking over Bernstein’s sexual excesses as Peyser does.

Burton simply tells a story. He appears to rely more on the Bernstein archives and the correspondence than on his own investigations. The facts, however, are engrossing. He sees Bernstein’s life in great dramatic arches, which are surely oversimplifications--one of Bernstein’s great attractions was the sheer complexity of his life--but that life did have its share of genuine theater, full of public incident and inner conflict. First there was the provincial youth, the boy genius growing up in Boston suburbs with Russian immigrant parents, his father a pragmatic salesman of beauty supplies and devoted student of the Torah.

Though Bernstein had to fight his father to enter a life of music, there seems never much question that he was destined for it. At an early age he already mesmerized everyone he came in contact with, from piano teachers (one, Helen Coates, became his devoted personal secretary for the rest of her very long life) to the siblings and friends he organized into impromptu kid summer stock opera companies.

At Harvard, Bernstein became sophisticated fast and made a mark early. By the time he graduated he was already part of Aaron Copland’s circle. He made New York friends, such as Adolph Green and Betty Comden, with whom he would soon write hit Broadway musicals. He was taken under the wing of Serge Koussevitzky at Tanglewood, and his career rise was meteoric. With Koussevitzky and Copland behind him, he was soon conducting everywhere. In 1943, at age 25, he made his famous Carnegie Hall debut, conducting the New York Philharmonic in a Sunday afternoon national broadcast as a last-minute substitute for Bruno Walter, garnering a front page New York Times review--and he was famous. His first symphony, the “Jeremiah,” was an instant success the next year. It all kept happening faster and faster, and he just got more and more famous. By the summer of 1957, he went from one of the most celebrated Broadway openings of modern history, “West Side Story,” which looked as if it could pave the way to a new kind of American musical theater, to assuming the helm of the New York Philharmonic a few weeks later.

Bernstein’s great ascent was accompanied by much self-doubt, however. Burton briefly develops the theme of duality in Bernstein’s character (as much as any theme can be developed in such a purely expository approach). Bernstein was constantly torn. Should he be composer or performer? If performer, was he conductor or pianist? Whether composer or performer, was his place in high art or in popular art? Was he teacher or entertainer? Was he gay or straight?

For a while Bernstein thought that he could have it all. In the summer of 1941, for instance, Burton presents Bernstein at Tanglewood absorbed in conducting one month, composing the next; one week he might be flirting with a “charming” boy in the box office, the next discussing marriage with a beautiful woman. “I suppose it’s a little crazy to do all the things I do,” he told a journalist a few years later, “but that’s my curse.”

In our Multicultural Age, those conflicts seem now more blessing than curse, and we now appreciate Bernstein precisely for them. That he brought serious purpose to the Broadway stage and some real popular theater flair into the concert hall proved just what each needed. But while those forces in his youth made him so appealing, they also in the end tore him apart. After a protracted and hesitant five-year engagement to Chilean actress Felicia Montealegre, Bernstein finally married her in 1951 and raised a family. When he became music director of the New York Philharmonic, he concentrated more on conducting than composition, and built the most brilliant career any serious American musician has ever known.

By the end of the 1960s, his life seemed to him to be falling apart. Depressed about his lack of composing successes, weary of a mostly heterosexual lifestyle, he resigned from the New York Philharmonic, and a couple of years later left his wife for a young man. He manicly roamed the world, winning over Europe. He composed weird melanges, such as “Mass” (for the opening of the Kennedy Center in Washington), a Jew writing a Catholic Mass as hippie mixed-media ceremony; it was derided in serious music circles when premiered but has now come to seem prescient postmodernism.

Burton chronicles the sexual dalliances, listing all those young men who passed through Bernstein’s later life. He doesn’t fail to present the regal character Bernstein became at the end of his life, traveling with his lordly entourage. He reveals a conductor who had gotten so out of control that he was actually competing with one of his daughters for the sexual attention of a young pianist, Justus Frantz. He labors over Bernstein’s terrible guilt that followed him through the rest of life, after the death of his wife from cancer in 1978 (Bernstein had returned to her at the end). He shows him to be a composer of ever greater insecurity, finishing some projects but not getting very far on many others, including an opera based on “Lolita,” which he planned to write for the great German baritone, Dietrich Fischer-Dieskau, as Humbert Humbert, and a Holocaust opera that obsessed him at the end of his life. And we get a morbid, blow-by-medical-blow account of Bernstein’s grim last days.

A few careless mistakes make one question Burton’s musical insights altogether, such as referring to Pierre Boulez as a minimalist in 1959, long before minimalism came about as a reaction against Boulez. A typo at the end, where Bernstein collapses dead in Wagner’s arms (rather than those of his friend Michael Wager), is so cosmic that it would surely have amused Bernstein. Fortunately, too, Burton’s blandness makes Bernstein less self-promoting than might be expected, given his love of speaking to Hollywood Bowl audiences when he served as guest conductor a decade ago.

But one misses far too much the life of the mind, of the musical and intellectual and spiritual forces that shaped Bernstein. The most fascinating aspect of Bernstein is that his mind was as hungry for knowledge, for understanding and for art as his body was for sex and food and his ego was for fame. And both Bernstein’s greatness and weaknesses came from his inability and unwillingness to separate them. Bernstein was not a subtle man, but he was a deep one, and that amazing life force may have led as close to outright musical transcendence as any musician has ever gotten. Somehow, 21 more Bernstein books doesn’t seem excessive.