In this year of big jazz centennials — 100 candles for Ella, Monk and Dizzy, and for the Original Dixieland Jazz Band’s first recordings — it’s easy to overlook an event that once loomed large over jazz history: the closing of New Orleans’ open-prostitution district Storyville, under pressure from the wartime U.S. Navy, which couldn’t keep its sailors away from the place.

Storyville was shut down at midnight on Nov. 12, 1917. Twenty-five years after that date, even casual jazz fans knew what that closing led to: an exodus of musicians from New Orleans to Chicago, the setting for the next phase of jazz evolution.

As history or legend had it, jazz had been nurtured, if not born, in the parlors of Storyville sporting houses, where Jelly Roll Morton himself might tickle the ivories. This birthed-in-a-whorehouse narrative made for lurid copy, underscored the music’s humble roots, and needled musicians who were tempted to dress jazz in too much finery. By 1946, when the critic Rudi Blesh published Shining Trumpets (A History of Jazz), “the district” (as its denizens called it) sounded like a cross between 52nd Street in its heyday and 1935 Kansas City. Music poured from every window, and paraded down the block.

The night of Nov. 12 had been extravagantly described in 1939 by Charles Edward Smith, in Jazzmen, the pioneering history that had really given the story legs. “As the evening wore on the musicians came out of the houses, one band after another, and formed into line,” he wrote.

Slowly it marched down the streets, Iberville, Conti, Customhouse. As it made its solemn stand it played ‘Nearer My God to Thee’ — plaintively, like the brass band on the way to the graveyard. On Franklin Street, prostitutes moved out of the long-shuttered cribs, mattresses on their shoulders. The brasses moaned, while the clarinets sung shrilly above them.

Hollywood also staged the end of Storyville, in a couple of movies that glanced at jazz origins. The district is never named in 1942’s Syncopation, where Basin Street is to be shut down at midnight, for unspecified reasons (as if jazz-friendly viewers could fill in the blanks).

At a crowded African American cafe, as midnight ticks near, the Louis Armstrong stand-in Rex Tearbone (Todd Duncan) says a farewell to the old times, declares he’s off to Chicago, and goes into a triumphant and vaguely military cornet blues. A sympathetic white beat cop pushes back the minute hand on the bar clock, giving the revelers extra time.

Lush, seedy Storyville is an explicit presence in the riotously uneven New Orleans, from 1947 —the one where Billie Holiday plays an opera singer’s maid. This film gives the events of Nov. 12 treatment worthy of a Biblical epic: it’s a capital-E Exodus. In this telling, Storyville’s residents are evicted, and all businesses closed. As midnight nears, musicians gather in their hideaway, and Armstrong (as his ageless self) says a few words, calling for one last, slow tune.

Someone asks Billie’s character to put words to what they’re all feeling. She gets a faraway look in her eyes, and starts riffing on Satchmo’s elegy: “The law stepped in / And called it sin / To have a little fun.” Then her listeners join in on the refrain. The “Farewell to Storyville” sequence — the song’s credited to Spencer Williams — is the only time New Orleans approaches a conventional musical: a spontaneous outpouring of heartfelt song.

Outside, police line the streets, and the crowd (still singing and playing) joins the area’s stunned residents, toting bedrolls and baggage: it’s the Jazzmen version writ large. The musicians duly disperse to Chicago, and wider fame.

Pops would again help stage the end on the mock-documentary TV series You Are There, in 1954. This time he played King Oliver, blowing till midnight at Pete Lala’s Cafe. Armstrong serves up some of his mentor’s licks, duels (out the window) with a brash cornetist across the street, and performs an anachronistic “When the Saints Go Marching In.” (His All-Stars played Oliver’s band, with white drummer Barrett Deems in blackface.) But by Louis’s own account, Oliver had left Lala’s before the final night. The end of Storyville had entered the realm of fantasy: a tabula rasa to impose any meaning on.

In time, historians chipped away at the notion of Storyville’s closure as a watershed event. In the revisionist view, the district had been fading for years, as Armstrong admitted in his 1954 memoir, Satchmo: My Life in New Orleans: “Even as a boy I could see that the end was near.”

Soprano saxophonist Sidney Bechet was among those who discounted the district’s influence: the brothels employed only a few pianists, after all. Besides which, musicians had been leaving town for years; Morton was long gone, the Creole Band had crisscrossed the continent, and the (white) ODJB had conquered New York.

The exodus came to be seen as part of the Great Migration of African Americans from the South to points north and west. In The Making of Jazz, from 1978, James Lincoln Collier decreed: “The role of Storyville in the birth of jazz has been overplayed by the early writers,” and the closing itself got half a sentence. Even the movies calmed down. In Louis Malle’s 1977 Pretty Baby, about Storyville prostitutes, the closeout is humdrum: the women pack early, ship their stuff ahead, and leave in daylight. But their Jelly Roll-esque pianist is bound for Chicago.

Thomas Brothers, in his 2006 book Louis Armstrong’s New Orleans, suggests we’ve come to underestimate Storyville’s importance — and that’s no less true now. The brothels did after all support a satellite entertainment district, however weakened by 1917, and business took a hit when the mansions closed — even if New Orleans musicians already understood they’d have to move north to connect with a wider audience, and better money.

Up north, by the ’50s, Storyville had become a brand of sorts, its name a shorthand for the outlaw roots of jazz. Early in that decade, Boston saw a series of clubs called George Wein’s Storyville — so named, Wein wrote later, “to prove that I wasn’t ashamed of jazz’s seamy origins.” Wein then founded the Newport Jazz Festival, which now operates an indoor Storyville Stage, where solo pianists and parlor-ready combos play in an atmospheric setting, acknowledging colorful olden times without getting too specific.

But you can’t talk about the closing of the district without bringing up the seamy side all over again — which may explain why we didn’t hear much about the end of Storyville in advance of its centennial. Seaminess sets the wrong tone, in an age when jazz chases corporate and institutional sponsorship. As catchphrases meant to lure honey go, “born in a whorehouse” serves less well than, say, “America’s classical music.”