They are the kind of words that give record producers ulcers and bald heads: “Hey, I don’t have my horn.” On March 29, 1954, Miles Davis uttered that phrase to producer Bob Weinstock when he forgot to bring his trumpet to the recording session. Jules Colomby, who worked at the studio, announced he had an old trumpet in the trunk of his car and hurried to retrieve it, but knew “the horn was full of leaks” and doubted that even Miles could make it sing. When Davis took the trumpet, he pressed each valve and immediately counted off the tempo, without saying a word. And sing the horn did. “I couldn’t believe how beautiful he could make that trumpet sound,” Colomby said. “Forget about take two, it was one of the best records he’d ever made.”

The song was “Walkin’,” the title track of an album that would later be known as the first in a new furious style of jazz—hard bop—and had the distinction of being one of the few records Davis would look back on with pride at the end of his life. Hard bop was already the third style of music that then-28-year-old Davis had developed (after bebop and cool jazz), and he was only five years away from recording Kind of Blue, a prodigious and transcendent work that has, for many, become the very definition of jazz. By the end of his career, which also included forays into film and painting, Davis could argue that he originated as many as five or six distinct styles of jazz—if the music can be so easily classified. Few other jazzmen even mastered as many as two of the music’s complex stylistic shifts.

Jazz doesn’t grow legends any larger, or harder to figure, than Miles Dewey Davis III, born in 1926 in Alton, IL. He lived on the leading edge of jazz, learned to make music without chords, and befuddled or disappointed his audience as often as he delighted it. Somehow, Davis became wildly popular despite his notoriety for ignoring his audience when he performed or leaving the stage during sets after playing just a few notes. The key to Davis’s music, it was said, lay not in what he was playing but in what he was thinking.

And no one could ever really figure out what was going on inside Davis’s head, even as his new way of conceptualizing jazz—holistically, as a process, as a feeling—was making music history. He was spiteful of the press, and when he did grant interviews, he spoke critically and paradoxically of his music, personal life, and friends. He was shy and vulnerable, arrogant and abusive, more fashionable than he was technically proficient on his horn, exceedingly difficult to work with, and so cool and so secretive that he effectively engineered his own ascension to cultural deity. To fill the void of the unknown, some of jazz’s best tall tales have been spun about Miles.

In So What: The Life of Miles Davis, John Szwed, a jazz scholar and Yale professor, makes it his business to cut through the mythology and contradictions to produce, in his words, “a meditation on Miles Davis’s life,” that corrects the mistakes and misunderstandings of previous biographers. Since Davis’s death at age 65 in 1991, he has been the subject of more than twenty books, including biographies, memoirs, and critical studies. Unfortunately, according to Szwed, some of those authors—including Davis himself and Quincy Troupe, who together produced Davis’s autobiography in 1989—were too enamored of the fanciful rumors about their subject and created enjoyable but fictive reads.

As a response, Szwed has created a meticulously researched, authoritative tour of Miles Davis’s life; its highlights and attractions are the gigs, recording sessions, albums, and the revolving-door roster of musicians Davis worked with. Szwed’s knowledge of jazz is dizzying, and for a jazz aficionado, So What could easily become the Kind of Blue of Davis biographies, where Szwed strips it all away, leaving the bare essentials to speak volumes. But for everyone else, Szwed’s commitment to the musical minutiae, from the unreleased takes down to the nuances of album liner notes and music politics, is also the book’s main failing. It’s a portrait of jazz by brute force—in detached words and excruciating detail—with only occasional forays into the creative genius or vamps of poetic contemplation that Szwed uses as lively hooks instead of the melody. If Miles Davis’s life can be likened to a 78 rpm, So What is like the needle on a vintage Philco turntable, designed to scrape the surface, to mimic the tiny contours of Davis’s experience.

Szwed has two things working against him. First, as he notes in his survey book Jazz 101, writing about jazz is twice removed from the real thing; words inadequately express what’s been documented in records, and records are a crude proxy for live performances.

The other part of Szwed’s problem is Davis himself. The man was an “enigma” who “even with the distance of time…resists interpretation.” He let so few people get close to him that, in the absence of reliable interviews or autobiographical writing, any biographer is an outsider who must swing to the music of conjecture, necessarily from the points-of-view of others. And Szwed must rely heavily on the dirty and depressing details previously published about Davis’s physical deterioration, unforgiving grudges, coke habits, and run-ins with the law. When Szwed finds irreconcilable accounts, he includes them in full contradiction. He doesn’t have all the answers, nor does he purport to. On the one hand, this makes So What one-stop reading on Davis. On the other, it’s far from a final word: “I would be surprised, even distressed, if what I have done or not done doesn’t spark yet another Davis biography,” Szwed proclaims.

But So What, despite Szwed’s insistence to the contrary in his introduction, is much more a musical study than a biography, an idea that itself isn’t so disagreeable. It was often said that Miles Davis and music were one entity. “Everything he did or saw had musical meaning,” one of Davis’s many lovers once recalled. Szwed writes: “Miles Davis was the sound of his trumpet. It was a sound that was deeply personal to him, and almost mystical in its source and power…” Even Davis’s personal life had musical consequences: fights with John Coltrane or Charlie Parker, or afternoon swims at a friend’s house that turned into experimental music sessions all affected the make-up and sound of the Miles Davis troupe.

Another lover once commented, “He wasn’t always Miles: sometimes he was only Dewey Davis.” Perhaps this is where the distinction lies: a meditation on Miles is an investigation of his music, and Dewey Davis is the alter ego for whom so many writers have been searching, a man who left so much and so little of himself behind.

As Szwed boils away some of the Miles fantasy, he is not out to defame Davis nor to deny him his legendary status. That would require moving mountains and destroying millions of records. In fact, you get the sense that on some level, Szwed takes great pleasure in hearing the most outrageous, unsubstantiated tales about Davis told by aging hipsters, but simply finds Davis’s aura to be more inspiring within the realm of nonfiction. Perhaps as a compromise, some of the verified anecdotes read as folklore—as the March 29 recording session does—to keep the Davis mystique alive as Szwed tells it to us straight: “He once flew all the way to Mexico just to hear Joe play [“74 Miles Away”] with Cannonball.” Similarly, some of Szwed’s descriptions place Davis on the tallest iconographic pedestal: “The breakups of Miles’ groups were discussed with the passion of baseball trades, and the radical stylistic shifts that inevitably followed were dissected like great movements in painting.”

And Szwed often chooses his quotations and references for their mythic qualities: “Vibraphonist Milt Jackson used to say that you could get a Ph.D. in music after just one set at Minton’s,” in New York City. Or this, from Davis, on the benefits of cocaine: “If you play a trumpet or any instrument, any drug like that, or brandy, will help you make up your mind quicker about certain things. So will firecrackers, but you can’t snort firecrackers.”

But, in the end, Szwed doesn’t need to meditate very hard to present Davis as a monarch of jazz; Davis did it himself. In one illuminating joke, Szwed makes it clear just what it meant to be Miles Davis: A jazz fan dies and passes to the other side. With St. Peter, he heads to a crowded club and recognizes the other customers as Lester Young, Billie Holiday, Thelonious Monk, and Charlie Parker. The jazz fan sees a man, with his back toward the rest of the crowd, dressed in black, sitting at the far end of the bar, and asks St. Peter, “Who’s that?” “Oh,” St. Peter responds, “that’s God. He thinks he’s Miles Davis.”