MISIA! A solo noun, long favored as badge by so many iron-willed professional French females, from Rejane to Regine. If she was not in fact French, still less a professional, her will grew stronger than mere iron, tempered though it was with gold.

Misia! One name. But beneath the silk hiss of those syllables lurked as many Misias as there were geniuses to depict her. Renoir painted seven portraits; Lautrec portrayed here too, as did Vuillard to sublimate a lifelong unrequited love. She was godmother to Picasso's first child. Cocteau said: "She has a talent for walking, laughing, putting one in one's place, handling a fan, getting into a carriage, designing a diadem." If Gide never took to her ("she plays the piano in an 'artistic' manner . . . which I dislike so much . . . more suitable for displaying the temperament of the performer than the quality of the piece"), Mallarme gifted her annually with pate-de-foie gras and homegrown poems (all now lost, alas, except for one quatrain inscribed on a Japanese fan, with her name misspelled "Missia," whch indicates that the French did not pronounce the single "s" as a "z"). Stravisnky: "I embrace you thousands and thousands of times very warmly." Satie: "Dear Madame, are you not a magician?" (though when she committed the cardinal sin of interfering with his creative activities, he announced: "Misia is a lovely cat -- so hide your fish"). St.-John Perse: "Dear friend whom I love, you are there, who come from no place on earth." Reverdy: "Dear Misia, I curse the obstacles that separate me from you. You are a piece of my life. A blue piece. . . ." (She herself claimed, "I've had only husbands, never lovers," and passed Reverdy on to her closest friend, Chanel, "who had only lovers, never husbands.")

Misia! She was the clay from which Proust fashioned the egret-coiffed Princesse Yourbeletieff as well as the less glorious but more powerful and crassly cultured Madame Verdurin, the wise and wealthy bourgeoise who, though sometimes a false friend, was ever a true art lover. (The present writer's dearest companion during the 1950s, the late Marie Laure de Noailles -- herself granddaughter of Proust's model for the Duchesse de Guermantes -- although probably more "creative" and surely as rich, molded her style around Misia: a day never passed, or a night, without Maria Laure remarking on how Misia did, or would have done, this or that.)

Yet who indeed was Misia, that such noble swainss commended her? The answer is found in a book which tells all you will ever need to knw about Madame Misia Godebska Natanson Edwards Sert who, though still largely unknown to Americans, was the single most influential dilettante in European art during the first three decades of this century.

Born of a wealthy Polish sculptor in 1972, Misia Godebska was one year older than Colette, though she always posed as 10 years younger, having with her own hand counterfeited her passport. Raised in Belgium in a milieu of privilege -- she was never to know any other -- Misia imposed her independence at 14 by running off to London where she lived friendless for several months. Returning to Paris she became a star student of Gabriel Faure; though she remained an amateur all her life, her piano skill was praised by everyone from Liszt to Eddie Duchin. At 15 (or was she really 25?) her entire dowry went into a trousseau for the wedding with Thadee Natanson, distinguished founder and editor of La Revue Blanche. Sloe-eyed and moon-faced, creamy-skinned and statuesque, effusively intelligent and passively carnal (though apparently, despite the scandal of three eventful divorces, a mostly faithful spouse), Misia now began a career modeling for fledgling masters and became, as drawn by Bonnard, her husband's first cover-girl. But the magazine's every policy was also in her hands; not an intellectual, Misia's instincts were nonetheless sound in matters literary. As a salonniere and coeditor she took full advantage of her access to the leading minds and talents of the Belle Epoque. Natanson was to offer her the most blissful and purposefully elegant period of her existence. The '90s were halcyon years of exploration, of a honeymoon in art, above all of acceptance -- and gold is a grand entree.

The century ended with a loss of her innocence, through new gains of gold. Alfred Edwards, vastly moneyed as publisher of Le Matin, vastly manipulatory and vastly vulgar (a coprophiliac to boot), decided, with the masochism typical of sadists, that he loved Misia Natanson and would die unless he had her. He persuaded his own wife to persuade Misia to become his mistress. When Misia refused he divorced his wife, and coerced Natanson, whom he has meanwhile bankrupted, into selling him Misia. Thus she emerged all-powerful among the richest women in France and "began to feel the troubling, the almost sexual stir of worldly ambition." (In 1908 Natanson showed the world his version of the marriage breakup in a lesbian melodrama, Le Foyer, revived as recently as 1938 by Max Reinhardt.) The next years meant renouncing her own work on La Revue Blanche, but they did bring the friendship of such valiant workers as Valery, Ravel, Arnold Bennett, who would join the Edwardses on the yacht Aimee to cruise through the canals of Europe. With all her intense desirability, Misia was no exception to the unspoken truth, that history's greatest femmes fatales are never so much "good in bed" as stylish hostesses and shrewd accomplices. But the years also brought a heavy dose of fin-de-siecle ennui aggravatd by Alfred's abject jealousy which, not unpredictably, dissolved into indifference when he fell in love with a scheming young actress. In her anguish Misia was not above abetting her husband's infidelities, like the wife before her. But this union too collapsed after four years, leaving Misia aggrieved, alone, 36, and well off.

Being well off was no hindrance to her rapport with Serge Diaghilev. From the minute she introduced herself merely by approaching his table at Prunieres in 1908, until his death 20 years later, she was "the only woman" for the great impresario as well as his chief confidante. The affinity arose from the slavic temperament that mutually possessed them. Both were born in Saint Petersburg within a week of each other, both took luxury for granted, and neither was overburdened with scruples. "When the history of homosexuality is written," the biographers tell us, "Diaghilev will be seen as one of its liberators. After all only a few years earlier Oscar Wilde has been imprisoned for the 'crime' that Diaghilev displayed with so little concern. And in her way Misia was one of the most visibly liberated of women. . . . Neither was particularly gifted sexually, and both found sublimation in controlling their friends and lovers by other means. . . . They adored gossip and had talents for intrigue. . . . Their reading days were over (Diaghilev was seldom seen to open a book), yet both were exceedingly rich in that singular commodity called taste."

That single commodity should be qualified as taste-that-only-money-can-buy. Paradoxically, Misia's next and final husband, the Spanish painter Jose-Maria Sert, amassed a fortune by producing murals of a cheapness-that-only-money-can-buy. Still, he became the sole true love of Misia's existence, making her for a very long time supremely happy. Ultimately he too succumbed to "another woman," the exquisitely unstable teen-age Princess Roussy Mdivani, whom Misia also adored. Even after the divorce the three for awhile lived uneasily a trois. When Roussy died, Sert said to Misia, "If you had really loved me, you would not have let me go." But in public affairs he was a mensch, using his considerable influence during World War II to protect French Jews, among them Colette's husband, Maurice Goudeket. At his death in 1945, Misia, who survived him by four years, wrote: "With him, all reason to live ceased for me."

Her last years were poignant. As early as 1927 she and Diaghilev, blase in their fifties, began to suspect with some justification that art had been better in the old days; they referred to the efforts of their new proteges as "des petites crottes adorables" (delightful dung). As an arbiter of taste Misia was growing out of fashion, her eyesight was failing, so was her budget. Relying ever more heavily on morphine (less to ease pain than boredom), she was finally arrested as a common junkie and never recovered from the trauma. When she died at 77, it was Coco Chanel ("still trying to wrest the crown from Misia, unaware that it was no longer there") who prepared the corpse in Sert's canopied bed before allowing selected mourners, among them Paul Claudel, into the chamber. Toay Misia lies near Mallarme's grave in the small cemetery of Valvins overlooking the Seine.

A necrophilic glamour exudes from these pages as they draw to their close and toward our present, as though the coauthors (who in their research enjoyed the hospitality of the mightiest personages in Paris except precisely the one under investigation) were themselves falling in love with the heroine -- she to whom they accredit, willy-nilly, the love of all who saw her. Bewitched by a woman they never met, they are nonetheless able to project onto the reader their own fascination. Consider these writers, who are, from one standpoint, as intriguing as their subject.

If pianists Robert Fixdale and Arthur Gold did not exist, they would have to be invented to write this book. Immediately after the Second World War they became more than merely the best two-piano team: they commissioned what turned out to be the best in their medium's repertory from composers as diverse as Boulez, Poulenc and Cage. Except for Rostropovich, who single-handedly caused to exist the bulk of today's cello literature, no other living performers have served contemporary music more than Fizdale and Gold.

Private Maecenases like this pair are not often bred in the USA where foundations (sometimes) take care of subsidies. Although by birth Chicagoans and by address Manhattanites, they have ever eschewed the cozy American need for specialization. If they resemble Misia Sert not only as keyboard artists (though surely more capable) and as purveyors of new music, they are equally un-American in their wish both to interrelate the various arts and to hobnob with artists themselves: they are snobs in the true sense of the word (which derives from c'est noble). Like Misia they have always moved in the ballet world, mainly that of Balanchine, by whom their advice is heeded as it has been heeded by many a worthy poet and painter. Gourmet cooks, they have during recent years tended the food column in Vogue. Fizdale and Gold have been everywhere, known everyone, impelled like many another francophile American of their generation (they're in their late fifties) by a yearning for a time they never knew -- yet almost knew. Originally planning a book on Erik Satie, they finally gathered the just rewards of their labors in the haut monde into the present biography.

Roughly a half is taken verbatim from documents: Misia's Memoir dictated to her amanuensis, Boulos, and published posthumously in 1952; letters, principally from Satie, Stravinsky and Cocteau but also from Bonnard, Bakst and others; vivid phrases from other people's books. More unusual -- and which lends the last pages a touching authenticity -- is the fortuitous discovery of a cache of memorabilia from one Paul Uldace: Boulos' own unpublished diary; still other notes from Ravel, Colette and Vuillard; and a revealing chapter on Madame Chanel by Misia herself, originally exised from the Memoir. (chanel has vetoed the essay, saying that she planned her own memoir, to which Misia retorted: "It exists already in your account books.")

The other half is so shamelessly padded with purple conjecture as to be useless except as a novel. Unlike a Steegmuller or a Painter who in the exemplary studies of Cocteau and Proust confected high literature by seamlessly weaving verifiable quotes into every paragraph, Fizdale and Gold rely dangerously on their own fancy. ("Shivering with fear and delight, Misia would hold tight to her brothers' hands when they took her down to explore the huge vaulted cellars." "Often, turning from the piano, she would watch the poet [Mallarme] sailing on the pewter-colored Seine in the calm splendor of early evening.")

I, for one, am not convinced that Misia's celebrated taste -- if that word means discernment -- isn't better termed flair. Did she not, after all, on commissioning a set of murals from Bonnard, take shears to them so that they would fit her walls? (Reproached for lack of respect, she replied, "I don't respect art, I love it.") And was she not miffed by her friend Debussy's dislike of her friend Stravinsky's Sacre on the spurious grounds that: "Every time I hear Debussy's La Mer I cannot help picking out the five or six passages which are almost identical with passages in the Sacre"?

It is perhaps nitpicking to say that the authors meaninglessly label Debussy's Jeux a "cubist" masterpiece? Or that they regularly misspell Lanthelme (the sapphic demi-mondaine for whom Edwards divorced Misia, and who at 24 fell from the Aimee's deck and drowned in the Rhine)? Or that they seem to ignore, when calling Misia a donneuse, that to the French the word means stoolpigeon more strongly than it means benefactress? Or that in contending that Misia's "speech was salted with irony and peppered with four-leter words," they mean the three or five or six-letter words to which French smut is uniquely restricted? Or that they fall into the well-known trap of crediting Cocteau, and not Peguy, with the quip, "One must know how to go too far"?

More serious is the esthetic misreading, not to mention the continual belittling, of Cocteau. "That overlay of mockery that was [his] own cynical, slightly sinister veneer," is far off the mark of one who, though sophisticated, was as vulnerable as an infant, and whose "veneer" -- and core as well - pleaded loudly for love. "A little behind the avant-garde but ahead of society, Cocteau in the twenties was the epitome of the advanced artist as homosexual hero." But the avant-garde is never homosexual per se; even if it were, Cocteau was never (at least not in his public works, not even indirectly) a homosexual hero, as Gide was. "Cynical" is Fizdale and Gold's word too for Marie Laure de Noailles in their editorial about "her willingness to collaborate with the German," adding gratuitously that she was "brilliant, talented, and perverse [being] after all a descendant of the Marquis de Sade." If they are inexact where one's friends are concerned, how can one trust them with strangers?

Yet the weakness of any book about Misia lies not in literary quality or even in mislaid truth (this book, which will doubtless be the last word on the subject, is as good as Misia deserves), but in fact that she was everything except the real thing. Like, say, the Gerald Murphys or Natalie Barney, she became a self-promoting promoter. Because she was really just a hanger-on, to solve the mystery of what made her tick is only superficially necessary. Still, unlike the Murphys, Misia hung on in the most vital way: she sponsored art by paying for it.

The strength of any book about Misia Sert lies in showing how she openly responded to the principle, so rarely grasped by Americans, that artists are finally less in need of understanding than they are of ready cash.