In his auspicious introduction, author John Szwed angles So What less as a straight biography than as a "meditation on Miles Davis' life." His reasons are fairly practical, ranging from the number of existing Davis biographies to the jazz great's famous unknowability. But he also hints at the essence of his subject's allure: his standing as a bizarrely spectral omnipresence whose mystery proves so potent that an unveiling amounts to a sort of betrayal. Betraying an irascible figure who loved to be hated is a tall order, of course, but as he showed in his masterful biography of Sun Ra, Szwed stands uniquely well-equipped to reconcile life and legend against a jazz backdrop that's always threatening to swallow its characters. Balanced and evenhanded to a fault, So What instead casts Szwed as a writer frozen before the realities and myths surrounding Davis, a genius who begged to be slapped, praised, and puzzled over during his 65 years. Starting with Davis' middle-class boyhood in Illinois, So What takes a swift path to his musical calling, which brought him to New York by way of The Julliard School as an 18-year-old. A less-than-stellar student, he fell hard for the bebop brewing in the '40s, making his way as an outclassed but fiercely protected partner of saxophone legend Charlie Parker in the early days. Szwed devotes a lot of attention to the '40s and early '50s, painting a rich portrait of a musical world not yet sure if bebop was even jazz, and introducing the way Davis hit on his singular, brooding style from the start. Effectively transforming the trumpet from a showy catcall instrument to something more searching and debonair, he hit on a sound that married his quiet brooding with a classic fashion sense that included tailoring his suits short in the back to account for his slumped-over stage stance. Naysayers decried that sound as "white" from the beginning. Davis' conflicted racial politics play a somewhat subtle role in So What: Noting that race in jazz history "is never very subtle or well considered," Szwed chronicles Davis' ebb-and-flow dynamic over time, from his integrated Birth Of The Cool-era band to his white girlfriends to the bracing proclamations of his later years. Though the thorny issues of Davis' abusive history make periodic appearances, Szwed proves more interested in the man's music than his earthy presence. "Beyond anything else he might have been, Davis was the sound of his trumpet," Szwed writes. But too much of So What reports on Davis' startling evolution rather than responding to it, and accounts of style shifts and landmark albums get mired in talk of lineup changes and record-company dealings. Szwed spreads out in an unfortunately isolated "Interlude" chapter, which treats Davis' life and career to a rich, deep reading. But ultimately, So What reads like an undernourished biography, and a missed opportunity by an author who shows his strengths just often enough to mark his failings.