Looking back, probably over his shoulder, singing in his inimitable style, Frank Sinatra could insist that more often than not "it was a very good year." There have been 70 of them now, turbulent and rewarding, yet no one has come along to wrest away his title as the padrone of American popular song -- the greatest singer and interpreter in the history of that vast reservoir of sophistication defined by such names as Porter, Rodgers, Berlin, Van Heusen, Mercer, Cahn, Kern and the Gershwins.

No amount of fractious biography can undercut the remarkable artistry that has consumed Francis Albert Sinatra for the past half-century. He would be the first to bow to his influences and admire his compatriots. But if we judge him by his art -- which is as good a standard as any, and the one he would prefer -- then Sinatra, who turns 70 on Thursday, remains the master, the king of the hill, the top of the heap, as sensitive to the nuances of a lyric today as he was in his youth.

Sinatra's musical instincts, in sharp contrast to his social skills, have generally been astounding. When you come down to it, he doesn't just interpret his best songs; he assumes them, absorbs their implications, seeks out the universal in lyrics by an astounding array of craftsmen, personalizes them and hands them back, renewed. Sinatra never needed to write songs, he just needed to find them to inhabit. When he was finished, they were his. So were audiences around the world, who rightly perceive him as one of the most powerful entertainers of the last five decades, one whose influence has extended well beyond his music.

He has sung often enough about the end of an affair, but this is one love match that continues. It's true that the bobbysoxers, his first fans, tended to celebrate mass hysteria rather than real musical accomplishment. But, like the Beatles, Sinatra grew into his art. And for the most part, he's maintained the faith, singing well and singing long, working in and sustaining a gloried idiom whose history and worth have been virtually denied by the tyranny of youth marketing.

As time goes by, new generations may have a hard time understanding what the fuss is all about. They tend to read about one Sinatra, the public boor and bully who has become a permanent news item, when they should be listening to another Sinatra, the classic singer who gave words worth. It's fascinating that in recent years artists as disparate as Linda Ronstadt, Kiri Te Kanawa and Barry Manilow have all paid homage with clumsy replications of Sinatra's Capitol Records-era sound, assuming the protective coloration without ever touching his style or approaching his charisma.

Of course, how we remember Sinatra has a lot to do with our vantage point in time and the importance we place on art over personality. Those who came to Sinatra in his two periods of grace -- the last days with Dorsey and the subsequent solo career in the '40s or the triumphant renewal in the mid-'50s and early '60s -- don't see the current Sinatra, tuxedo-clad, graying, thicker in body than he is in voice. They look at him and see the bow-tied, hollow-cheeked youngster, a bony baritone engulfed in wide-shouldered suits; or the savant swinger with the rueful grin, snap-brim hat pushed back, tie loosened, trench coat slung over the shoulder, an embodiment of the romantic cynic.

And in that trick of cultural memory so basic to nostalgia and so important to art, what we see is what we hear -- The Voice, forever young. We are enveloped in Sinatra's natural, conversational manner, his masterful phrasing, his evocation of uncluttered emotions, all of it getting under our skin. All the dissonance of Sinatra's life can be resolved in that voice; contact dissolves doubts. He was a great communicator before you know who, and now when we see him, it's with all those contradictory strings attached and pulled.

What's been most astounding is Sinatra's artistic survival. We don't expect athletes to last into middle age, but we expect singers not only to go on forever, but to reinvent themselves constantly in contemporary contexts.

The length of Sinatra's career has forced him into many reinventions, and he's made painful accommodations at times. But all in all, he's managed to remain remarkably constant in the rapidly changing environment of popular music. Anchored in the sophisticated song writing that emerged in the '20s and '30s and continues to provide the core of his repertoire, Sinatra has endured through the big band era, the swooners, the crooners, the belters, the rockers and the rollers. Now, the hipster is back to square one.

The voice has changed, sliding, as Sammy Cahn once wrote, "from violin to viola to cello." Sinatra quit briefly in 1971, a period when his voice seemed eroded, vibrato widening, breath giving out, pitch wavering, high and low notes less attainable. But that simply set the stage for Ol' Blue Eyes' remarkable comeback, and in later years Sinatra has turned his weaknesses into assets: the voice -- darker, thicker, tougher -- services the songs in a new manner. His stamina diminished, he now tends more to up-tempo tunes that, like the showmanship and the mythology, mask his deficiencies. He still invests the ballads with rare artistry, but they tend to betray the passage of time.

One mark of enduring genius, of course, is being in the right time at the right time. Sinatra's emergence in the early '40s (postswing and big bands) and his revival in the middle '50s (prerock) illustrate the point. A romantic idol in the troubled times of World War II and one of the first singers to earn the adulation of a largely female audience, Sinatra advanced the art beyond the genial crooning of Bing Crosby, just as Crosby had advanced it in his time. After Sinatra, it seemed that the singing was never again as important as the song or the performance.

The subtleties and specifics of Sinatra's technique -- the peerless phrasing, the supple articulation, the intimacy that suggested Method Singing -- are less important than his impact. Other singers were more inventive, more adventurous, did individual things better; Sinatra was a total package. Intuitive, he nevertheless worked hard, expanding the boundaries of breath control to realize in his singing what he heard in others' playing. Sinatra had no formal training, but he had formidable instincts, which led him to adopt elements of the Italian bel canto school -- mainly those long flowing lines, the seamless legato that he also heard in Tommy Dorsey's trombone and Jascha Heifitz' violin.

Sometimes miscast as a jazz singer because he has so often surrounded himself with the cream of that genre, Sinatra's melodic deviations have seldom been extravagant, nor his embellishments particularly inventive (especially when he decided to improve a lyric). He's always been most comfortable within the straightforward conventions of popular song, which may be why he has touched so many people.

Even in his formative years with the Harry James and Tommy Dorsey bands, Sinatra was making his art accessible, a quality that would serve him well for the next four decades. Given the right material -- lyrics he could believe in, a melody that could enthrall -- Sinatra has always placed himself at the service of his song. What his most recent album, "L.A. Is a Lady," showed was that his Tin Pan Alley roots are as immovable as any oak's. When he has tried to sound current, or made commercial accommodations to contemporary songwriters, the result has been inelegant -- or worse, for Sinatra, unconvincing. On "L.A." he was reconciled on vinyl, as he has generally been in concert, with the tradition that bred and buttered him.

If there were golden eras in Sinatra's career, there were dark eras as well. The first, and probably the worst, came in the middle to late '40s, when Sinatra lost his credibility, his record and film contracts, his management, his family, his fans, even his voice. Humbled by Columbia Records and its pop lowbrow, Mitch Miller, Sinatra made the first of several remarkable recoveries with both Hollywood and Capitol Records in the '50s, recast as the hip swinger. It was a new identity that supported a new sense of purpose and resolve.

Ironically, some of Sinatra's greatest triumphs came at a time when rock was supplanting pop. While his compatriots fell to the side, Sinatra maintained both his audience and his convictions: From early 1958 to 1966, he didn't have any Top 10 singles but managed to produce 27 Top 10 albums. Still, by the early '70s, he was beset by voice problems and out of favor again.

Since then, he's enjoyed a decade of renewed success. Yet there's been no mellowing of a public personality that remains as complex as ever. Forty years after the press first turned on him, he is still an idol easy to tarnish: feisty and temperamental, blessed for his generosity and damned for his truculence, honored for his involvement in the arts and politics, chastised for his divorces, brawls and adolescent antics -- and berated for the company he keeps.

Sinatra's life, like his music, is a study in dichotomy. The voice invites you in, but the intimidating ego and Las Vegas mannerisms exclude. Inconsiderate and vengeful at times, he can also be, by many reports, warm, gracious, compassionate. He's blown his share of money on extravagant gestures, but he's also given away more than most individuals could ever dream of. In his time, he's known rejection in the highest and the lowest places, failure and frustration in many media.

Little wonder then that Sinatra is both the diamond and the rough, singing gracefully most of the time, behaving gracelessly some of the time. One suspects that, given the opportunity to do it all over again, he'd still do it his way, the same way.

At 70, Sinatra has nothing left to prove. His concerts now must be considered a risk; the instrument is, after all, not what it was, no matter how delicately or passionately it is handled. The damage comes not from a bad performance -- some of Sinatra's most recent appearances have been among his most triumphant -- but from a dilution of a compelling American myth. The arrogant Sinatra will always be forgiven by those fans who remember him as Frankie, and later Frank. But the singer who bridges memory and reality courts disaster when he insists on denying the end of his time -- particularly when one can turn back to pure, timeless recordings for comparison.

There's talk of a movie about Sinatra's life and career, covering the years between his youth in Hoboken, N.J., and 1953, the year he won the Academy Award for "From Here to Eternity." There's talk of Sinatra himself doing another movie, possibly a follow-up to "The First Deadly Sin." In retrospect, his movie career is less inspiring than his recordings, moving from slight but savory entertainments like "Ship Ahoy" and "Anchors Aweigh" to the dramatic breakthroughs of "Eternity" and "The Man With the Golden Arm" to such cloddish Clan-congregations as "Robin and the Seven Hoods," "Sergeants Three" and "Ocean's Eleven." Sinatra made as many bad movies as Elvis Presley, he just had the sense not to sing in all of them.

But in the end, of course, one must come back to the music.

Sinatra has often described himself as a saloon singer, and two images in particular reinforce that stance. One is the cover of "No One Cares," with Sinatra slumped at the bar, solitary, gazing forlornly into his drink, his cigarette burning down, while in the background men and women are warmly connecting.

And then there's "Only the Lonely," with the cover showing Sinatra made up in the tears of a clown. The album, which many consider his masterwork, is loaded with exquisite torch songs, gems like "Willow Weep for Me" and "Guess I'll Hang My Tears Out to Dry" and "Angel Eyes," with its coda of resignation, "excuse me while I . . . disappear."

The album's transcendent moment come in the Harold Arlen-Johnny Mercer song "One for My Baby," with Sinatra settling onto a stool for some quarter-to-three over-the-bar confessions. A languid piano underscores the hurt; a subtle wash of strings, or a mournful saxophone, brush by in the background.

And Sinatra sings it like his life depends on finishing the tale; unless he does that, he'll never walk away.

And when I'm gloomy, won't you listen to me, till it's talked away . . .

Well that's how it goes Joe, I know you're getting anxious to close

And thanks for the cheer, I hope you don't mind my bending your ear

But this torch that I found, it's got to be drowned

Or it soon might explode

So make it one for my baby and one more for the road.

During the 1984 Presidential Gala at the Washington Convention Center, Sinatra sang "One for My Baby" while Mikhail Baryshnikov danced it with Twyla Tharp's wonderful choreography. This time, it was the dancer inhabiting the lyrics, a meeting of two graces in a magic moment anyone could recognize.

That's the Frank Sinatra who remains intact in the heart.