"I DIDN'T KNOW Mozart was a person: I thought it was just another name for music," the six-year-old girl who made this remark summed up the phenomenon of Mozart better then all the superlatives that have been used to elevate the man's achievement. The business of finding Mozart "the person"--looking for the musician behind the music, making sense out of the limited store of facts and rumors--has occupied countless biographers over the years. And it is undoubtedly a formidable task to get the measure of a man whom Wolfgang Hildesheimer, the latest to make the attempt, calls "perhaps the greatest genius in recorded history."

This new biography by Hildesheim, an esteemed Mozartian, was widely acclaimed on its publication in Germany five years ago. Written in a fresh, distinctive style, this account refutes much previous speculation about the great composer's life and music, replacing it with scholarship and practical judgement. Much of the enjoyment in reading the biography derives from its flexible approach and its lack of a didactic single answer to the enigma. Hildesheimer freely admits that his work is only a contribution to the "concert of diverse voices," yet he hopes to alter that concert with his voice. He considers "the reader's power of imagination and willingness to imagine" an integral requisite for the appreciation of his discussion.

"We will not get close to Mozart," he states at the outset, and it is true Despite the interesting analysis of music and letters which pervades the text, the most frequent effect it produces is frustration--sometimes at a particularly annoying interpretation (as when Hildesheimer relegates The Magic Flute to "the lower ranks of sentiment") and sometimes simply at the inadequacy of the existing evidence on Mozart's life and thought.

Along with the frustration comes frequent disillusion; Hildesheimer does not balk at exploding romantic preconceptions. A famous reflective letter which Mozart wrote soon after his father Leopold's death--usually taken as evidence that the composer underwent profound emotional stress--is here traced directly to one of the era's popular books on philosophy; in addition, Hildesheimer observes. Mozart's first composition after the letter was "A Musical Joke." Hildesheimer also presents his own interpretation of Mozart's notorious tendency to indulge in "fecal comedy." The crude giggly figure of Mozart seen in Peter Sheffer's play "Amadeus" is, it seems, part of the unsavory reality of history. Other half-truths are taken up along the way and variously dispensed with: for anyone but a keen follower of trends of Mozartian interpretation, such discussion obtrudes more than it adds.

The picture evolves through a circular discussion of different aspects of the man, rather than unfolding in a sequentially predetermined order. In this sense it is an unorthodox biography. There His no chapters, no neatly presented "phases," no strictly chronological pattern in Hildesheimer's story. His introductory remarks on the problems of writing about Mozart spill over, undivided, into the first chosen issue of the biography.

Despite the many frustrations of the text, the flow of sympathetic and clearly intelligent ideas carry the reader swiftly along. Mozart is set convincingly in his period with an adequate array of related characters. The astounding achievement of his music is movingly set against the pecuniary and social tragedies of his brief life. The story is further spiced with a succession of sometimes amusing, and always appropriate, anecdotes. (We are told, for example, about the occasion in a Swedish maternity clinic when his Piano Concerto K 467 was successfully used to ease childbirth.)

AS HILDESHEIMER WARNED at the outset, this confident though unassuming biography leaves us with a still-unresolved composite of "an inconceivably great mind." All the cliched preconceptions--the angelic genius, the pauper-composer who hardly needed to think about the music he produced, the partier--are soon quashed. Hildesheimer, steeped for three decades in Mozart's music and history, shares with his reader the honest belief that his subject will remain "forever puzzling and unapproachable."

The almost continual creative activity of an intellect who towered so far above his society, and yet continually communicated with it and seemed to adapt to it, but who lived in it as a stranger, a condition neither he nor his circle could encompass; who grew ever more deeply estranged, never suspecting it himself until the end of his life, and making light of it until the very end--our imagination cannot accommodate such a phenomenon.

The task of interpreting genius lies almost entirely in the questions implicit in such a description--the ones Hildesheimer tackles and the ones he must leave unanswered. They bring him as close to the essence of Mozart as anyone is likely to get.