For the last 20 years, ever since "Funny Girl" opened to rave reviews on Broadway in 1964, Barbra Streisand has been a reigning star, first of stage, then of screen and record.

No less enduring than her fame, however, has been Streisand's reputation as the enfant terrible of modern show business. Time and time again, she has been portrayed as an artist of wildly unpredictable temperament who, in pursuit and defense of her exalted status, has seldom hesitated to be domineering, manipulative, boorish, abrasive, seductive, arrogant, vindictive or downright rapacious when she felt the occasion called for it.

Through the years, Streisand's fans have repeatedly reaffirmed their devotion by giving her million-sellers at the record bins and similar hits at the box office. Yet at the same time, there has been a lingering critical perception of her as a singer who often has abused her immense gifts in an almost slavish pursuit of musical trends. Pop, rock, disco, classical -- you name it, she's tried it. This same critical minority has faulted her for repeatedly lending her not inconsiderable acting talents to a string of lightweight musicals and dramatic souffle's -- most of which have, as they say, done "boffo" on the Variety charts.

Shaun Considine is an entertainment journalist and former public relations executive with Columbia, Streisand's longtime record label. In this unauthorized biography, he has made a diligent and even-handed attempt to weed through the critical prejudices and obfuscations of legend that cloud whatever realities lurk behind Streisand's jaded mystique.

Despite the author's even-handedness, however, those drawn to this book by his credentials as a contributor to People magazine won't necessarily be disappointed. There is ample material (though I sense little really new or startling) on Streisand's short-lived marriage to Elliott Gould, as well as her well-publicized liaisons with Omar, Warren, Pierre and Ryan (as in Sharif, Beatty, Trudeau and O'Neal). There is also a delightfully humorous account of her unsuccessful attempts to woo Robert Redford, her on-screen lover in "The Way We Were."

But the real emphasis -- and justifiably so, I think -- is on Streisand's music and her career. Considine, the former PR man, is on firmest ground when he brings his biographer's microscopy to bear on the deal-making and behind-the-scenes intrigues that enabled Streisand to surmount the overwhelming rejection and indifference greeting her earliest singing and acting efforts. (When Streisand first invited her own mother to see her perform, at a theatrical workshop in 1960, the elder Streisand was appalled and practically begged her daughter to stop fooling herself. Streisand later retaliated by banning her mother from the backstage of "Funny Girl.")

Considine has a fine ear for the comically self-aggrandizing hyperbole of show business argot. And he seems to take particular glee in chronicling the ineptitudes of his former employers at Columbia in their rather blatant mismanagement of Streisand's early recording career. (The label had rejected the singer as "too eccentric" before reluctantly signing her in 1962; her records have since brought an estimated $125 million into the company's coffers.)

At the heart of the author's rather nonjudgmental approach to his subject seems to be a tacit acknowledgment that, more often than not, popular genius springs from immense incongruities of character. Thus we encounter Streisand -- at the height of her career, with an estimated personal fortune of $50 million to $70 million -- still clipping coupons and sending recycled cards at Christmas. For her, we learn, the only irritant more insufferable than crowds of adoring fans is the absence of the same.

Unfortunately, we learn far too little of the origins of her talents and the roots of her often overweening personal dissonance. Considine has meticulously assembled great detail on the evolution of her multifaceted career (from the immense problems of staging "Funny Girl" to similarly overwhelming difficulties in bringing "Yentl" to the screen in 1982). Yet what we learn of her pre-show-business years takes up scarcely more space than do the details of her 1963 revamping of her hair style, or her 1967 decision not to get a nose job.

The Streisand who emerges on these pages too often seems a mere cardboard figure -- a one-dimensional montage assembled from press clips and secondhand anecdotes, rather than a flesh-and-blood human being. (The star herself refused to be interviewed without manuscript approval.) And it is this inadequacy, more than anything else, that makes this otherwise serviceable and entertaining biography at times ring hollow.

The reviewer, a Maryland-based free-lance writer, is the author of a biography of singer George Jones.