Was there ever an American musician in the post–Dylan firmament as mythologized as Gram Parsons? Consider: Parsons was a Florida–born citrus scion, a Harvard dropout, a confidant of the Rolling Stones, a glamorously louche denizen of the Chateau Marmont, and a Nudie–suit–wearing country–music connoisseur in the late sixties and early seventies, an era in which the Laurel Canyon singer–songwriter elite, of which he was tenuously a member, shunned even Elvis as dangerously retrograde. In his stints with the Byrds—arguably the biggest American band of the day—and the Flying Burrito Brothers, Parsons, with his maverick tastes and lonesome tenor, essentially invented country–rock. He was also a world–class inebriate who died in 1973 at the age of 26 in a Joshua Tree, California, motel. To top it off, his corpse was stolen—or rescued, depending on whom you talk to—by his road manager and set ablaze in the Mojave Desert.

So it's no accident that the Gram Parsons story, as told in a handful of biographies and a 2004 feature documentary (as well as celebrated by a slew of tribute records and concerts), tends to follow a fabulist script, one that Parsons himself was perfectly capable of burnishing. Born Ingram Cecil Connor III, Parsons was a wealthy Southerner who wanted you to know he was most at home, as he versified in the semi–autobiographical 1973 ballad "Return of the Grievous Angel," "with the truckers and the kickers and the cowboy angels." Lost amid the purple sage was the fact that the exalted family pedigree—Winter Haven's Snivelys, reputed to own 20 percent of the entire Florida citrus industry—was riven, like something out of Tennessee Williams, with alcoholism and despair; that Parsons barely lasted one semester at Harvard; and that while he was indeed invested with major talent, he spent prodigious amounts of energy and inherited wealth squandering it.

Now an encyclopedic and likely definitive Parsons biography, Twenty Thousand Roads, by David N. Meyer (Villard), gamely takes the measure of the man without fixing the legend even further in amber. Meyers, a journalist who teaches at the New School in New York, notes that Parsons "had everything: looks, cool, charm, charisma, money…?and threw it away with both hands." Nevertheless, "the most talented musicians in America would do anything for him." Why did they care? And, by extension, why should we?

Because despite a career that spanned barely seven years, Parsons continues to cast a long shadow over American popular culture. His famous white satin Nudie suit—embroidered with images of naked women, marijuana leaves, Tuinal capsules, and a blazing red cross (a chilling temptation of his actual fate)—now hangs in the Country Music Hall of Fame. Artists from Elvis Costello to Dwight Yoakam to Ryan Adams hail him as an indispensable guiding light. The Eagles, who rode a denatured version of his "cosmic American music" all the way to the bank, would have been impossible without him. His luminous solo albums, GP and Grievous Angel, commercial flops when released in the seventies, are now hailed as enduring classics thanks to his aching duets with Emmylou Harris, the muse and artistic soul mate who later built for herself the career Parsons should have had by carrying forward the torch of his vision. (Contrary to eternal speculation, Meyer declares that the lovers' clutch implied by their intertwined voices was never consummated offstage.)