In the century since jazz became a distinctive sound, the story of how the music came to be has emerged in several waves, starting with oral history interviews in the 1940s and ’50s, continuing amid a stream of memoirs by players such as Louis Armstrong and Jelly Roll Morton. Morton told his story to Alan Lomax, but Armstrong, a grade-school dropout, used his own typewriter to write Satchmo: My Life in New Orleans, which was published in ’54.

By the 1980s, scholars and journalists mining the memoirs and the many interviews at Tulane’s Hogan Jazz Archive discovered more varied sources, writing histories that have become steadily more textured. But from the earliest interviews one thing was clear: For all the dancing and rocking times associated with the music that shaped the identity of the city we know today, the founding players came from hardscrabble origins. Few made it as far as high school. They faced huge odds, as blacks, to make a decent living in the segregated South.

The American idea is steeped in the myth of endless space. The westward migration of pioneers, like the ethnic Europeans who crossed the Atlantic fanning out in cities of a young nation, are images of a national saga. The more we learn about history however, the more we confront realities to dampen the myth. Pioneers, to cite but one example, slaughtered American Indians who had first purchase on the land with treaties that often amounted to theft.

The deep poverty from which so many early jazzmen rose – a world away from Jazz at Lincoln Center or NOCCA – is obscured in popular perceptions of how jazz began. Like artists of every age, blacks and colored Creoles who forged the idiom wanted to make money at what they did.

That is a leitmotif in John McCusker’s impressive new book, Creole Trombone: Kid Ory and the Early Years of Jazz (University Press of Mississippi.) A veteran Times-Picayune photographer who shared in the Pulitzer Prize coverage of Hurricane Katrina, McCusker’s career at the paper, like that of so many others, has come to an end. As the paper sacrifices institutional memory to the Newhouse money machine, McCusker has a spotlight, and his book is sweet vengeance.

McCusker spent years scouring libraries, archives and census data in reconstructing Ory’s ancestral lines. He delivers an inspired take on Creole. Despite the French-sounding surname, the father came from German stock among the area landowners. “With a white father and a mother of mixed ancestry, Ory was as white as he was black, and this was certainly at the heart of his Creole identity in a racial context,” writes McCusker. “Still, self-taught identity is one matter; the law is another. Though he had straight hair, Anglo features and red skin, Ory legally may as well have been black as coal.”

Born Christmas Day 1886 in LaPlace, a mile behind Woodlands plantation, Ory was orphaned in mid-adolescence. He worked as a field hand while making music on makeshift instruments. Mesmerized by brass bands that toured the plantation belt, he started his own group and, after forays to New Orleans, got his first horn. He left the plantation in 1907 with an angry overseer shaking a fist at him as the train pulled away.

Unlike Creole bandleader John Robichaux or clarinet master Lorenzo Tio Jr., Ory was unable to read sheet music. Culturally, he was more like Uptown blacks, descendants of slaves who played by ear, improvising on what they heard. Ory was a hustling troubadour who hired wagons to haul his band, the musicians playing advertisements of the gig that evening or night. A showman in the truest sense, Ory formed a potent alliance with Joe “King” Oliver and gave Oliver’s protégée, a teenaged Louis Armstrong, his first break.

“Debutantes wanted the Ory band so they could dance the turkey trot and the bunny hug,” writes McCusker. “Ory played A-list parties with such success that he cut into Robichaux’s market … Ory’s group helped the music cross over the racial and cultural threshold. Ory’s group delighted whatever audience lay before them: a Saturday night in Storyville, a Sunday afternoon brass band parade or a Friday night hotel ball. The band traveled through different worlds, all existing in the same geographical space.”

The wisdom in that last sentence, precise as a pinpoint yet simply stated, echoes through the book. Creole Trombone is an able biography and one of the smartest books yet written on the origins of New Orleans jazz. McCusker debunks the notion of Storyville as a happy musicians’ haunt; the sex trade and raucous milieu carried its share of excitement and the music ran hot to meet expectations. But the church parades, picnics, outdoor concerts and low-rent balls were venues for different stylistic approaches through those different worlds in the same geographical space. In 1919, a Storyville club owner named Pete Lala, in thick with the mob, tried to cut in on Ory’s success at sponsoring dances. Fearing for his life, Ory and his wife moved to California.

In the mid-1920s, Ory reunited with Armstrong in Chicago, and earned a major place in history on the Hot Five recordings. “Muskrat Ramble” is his most famous composition. His name lives on with “Do What Ory Say” and “Ory’s Creole Trombone.” He spent his later years on the West Coast and Hawaii, working slowly on an autobiography he never finished. McCusker persuaded the family to give him access to the manuscript and uses it wisely, seasoning the narrative with episodes of Ory in his own voice.