The man who was Sinatra.

FRANK SINATRA embarked recently on something called Frank Sinatra's Diamond Jubilee World Tour (With special guest Corbett Monica"). His name was also in the papers again: Judith Exner has described anew how Sinatra helped bring her boyfriends John Kennedy and Sam Giancana together. (Giancana lent Kennedy a generous hand in Chicago during the 1960 campaign, and shortly after the Bay of Pigs disaster, Mrs. Exner says, the two met in a Chicago hotel room to plot the death of Fidel Castro.)

Sinatra also made news - or rather, had news made about him - when Kitty Kelley wrote that he'd had a White House fling with ... oh, you remember. Having been the subject of Miss Kelley's last bio, he must have thought he'd paid his dues to her. Little was yet to come.

However false and outrageous such gossip may be, Sinatra has made himself vulnerable to it. His celebrity is the enemy of his genius. Most young people today probably think of him as an old Las Vegas entertainer in a toupee who signs "My Way," "It was a Very Good Year," and an especially dilapidated version of "Bad, Bad Leroy Brown," interspersed with double-entrendres that draw guffaws from the drunks in the audience. Phil Hartman of Saturday Night Live catches this Sinatra, obtusely sure he still defines hip, in a hilarious imitation.

For thirty years, since he left Capitol Records to launch his own Reprise label, Sinatra has been freeloading on his own legend. He has forced an admiring public to associate him with the Rat Pack, ugly feuds with the press, thuggish bodyguards, a self-advertised appetite for booze & broads, and some dpressingly soggy singing. Obsessed with his legend, he has done his best to destroy it. Fortunately, there is more Sinatra than tailored autobiographical schlock like "My Way," retrospective albums, of greatest hits (complete with self-congratulatory narration), and a seris of apparently self-bestwed nicknames (chairman of the Board, Ol' Blue Eyes).

Sinatra's career falls into three neat if unequal periods . Early Sinatra, the bobby-sox swoon of the Forties, was an excellent crooner whose originality is captured by Gene Lees in his book Singers & the Song: Sinatra was the first vocalist to understand the implications of the microphone, which "made possible speech-level-level singing." Journalists made fun of sinatra's habit of gripping the old standing mike, tilting it toward or away from himself: "They did not understand that he was playing it." Voice and mike became one instrument, and Sinatra knew exactly what sound it was producing. Other singers just performed in front of the mike, trusting it to reproduce their performances. By making it his partner, in effect, Sinatra created an intimacy through broadcast and record. There was no need to "project" the voice, as in opera singing; sound engineering had made the pear-shaped tone obsolete, stagy-sounding. (Marlon Brando achieved a parallel effect on film by abandoning the large gestures and vocal resonance of traditional stage-acting.)

But there was much more to Sinatra's technique. With superb breath control (learned from Tommy Dorsey), he broke lyrics into speechlike phrases, subtly unpredictable. Each not became a unit less of music than of meaning. That his style was praised for "sincerity" was the triumph of his extremely self-conscious art.

The enormously popular Early Sinatra faded in the late Forties. Record sales plummeted, his sweet voice unaccountably turned to a croak, and he left his wife to chase Ava Gardner. His career seemed finished until he landed the role of Maggio (for which he won an Oscar) in From Here to Eternity and began Middle Sinatra, the nonpareil of American pop singers. With Nelson Riddle, billy May, and Gordon Jenkins (but mostly Riddle), he recorded an amazing series of albums: In the Wee Small Hours, Songs for Swingin' Lovers, Only the lonely, Come Dance with Me, NO one cares, Nice 'n' Easy, and a dozen others.

Middle Sinatra was to pop music in the Fifties what Casey Stengel's Yankees were to the American League. He changes the whole sound of it. He was, in his own favorite word, swingin' now. There was less honey and more lemon in the voice, a transparent tone with a slightly acid edge. He sounded both tougher and sadder than he had in the Forties. He sand more up-tempo songs, and his gift for phrasing gave them a conversational ease, an irresistible new rhythm. He recorded dozens of standards, but they sounded different from the way they had before; only a bold singer would dare to record any of Sinatra's many signature songs.

Middle Sinatra could still croon, too. For inscrutable reasons (Ava Gardner was the only explanation anyone could think of) his ballads and torch songs seemed to carry infinitely deeper meaning and feeling than they had had in his youth. They were less pretty but more beautiful, sung with a kind of offhand conviction, like tales told late at night in a bar - the situation presupposed in one of his greatest performances, his 1958 recording of "One for My Baby," with Bill Miller's haunting piano accompaniment. In Nice 'n' Easy (1961) he rerecorded a dozen slow songs he'd first recorded on Columbia in the Forties; it remains his finest album. It reveals that his sense of rhythm is even more telling when he sings slowly than when he swings, every note audaciously delayed until it has to be sung. If you want to embarrass yourself, try singing along with it. Assuming you can reach all the notes (yes, Sinatra's range is underrated)' you'll find yourself consistently hitting them 'way too soon. The old master will show you up without even trying, you hasty pipsqueak.

In the Sixties, all too soon, came Late Sinatra, now entering his fourth decade. His first few Reprise albums were as good as his Capitol recordings; unhappily, most of them have never been released on CD and are no longer available. As the decade passed, he sang with less and less belief in the lyrics. Partly it was a matter of a relaxed styled becoming downright lazy; partly it was due to inferior material. He wasn't doing Rodgers - Hart, Gershwin, Porter, Kern, and Mercer songs any more; instead, he was goofing off with schmaltz like "Strangers in the Night," "That's Life," and, over and over, "My Way," his excruciatingly boastful theme song, which exposed a withered larynx and a degree of self-intoxication that could only make you blush for him. Without the rein of self-criticism, his talent deserted him.

The wonder is that this uncouth man once sang the best American popular songs, back when such songs were still being written, with such uncanny sensitively and finesse. A musical era ended at about the same time Sinatra quit singing seriously, when mainstream radio stations started playing rock. But a radiant part of that era has been preserved: Capitol has reissued nearly all Sinatra's albums from the Fifties, as well as a three-disc set of 75 of his best songs, The Capitol Years. Listen to a few bars of "I've Got a Crush on You," and you'll forget all about Kitty Kelley.