The waters that drowned New Orleans are the waters that established the incomparable city as a key port before the railroad replaced shipping as the primary vehicle of trade. They gave New Orleans a unique cultural character, blending elements of the continental United States with those of a Caribbean island. Cradled between the big dipper of the Mississippi and huge Lake Pontchartrain, New Orleans was a locus for the slave trade and known also for cotton, sugar cane and fishing. Yet to most of the world, New Orleans is chiefly associated with one export that it largely abandoned decades ago: a way of playing music called jazz.

You can still hear jazz, but aside from Preservation Hall, it has pretty much disappeared from the French Quarter, finding hospitable bars and restaurants on the other side of Canal Street. There is an airport and a park named after Louis Armstrong, an invaluable archive at Tulane and Herman Leonard's photographs are everywhere, but jazz always had an uneasy life there. The chamber of commerce never did for jazz what Nashville did for country; it wiped out all traces of Basin Street and refused to preserve Armstrong's home.

So, humanity aside, what do we jazz lovers specifically owe to New Orleans?

Only everything.

It wasn't the sole place of genesis. The mobility of freed slaves after the Civil War guaranteed the spread of musical practices honed in the South. Ragtime prospered in St. Louis and the blues in Memphis. The journalist Lafcadio Hearn described syncopated black bands on the Cincinnati levees in 1876; two decades later, W. C. Handy took his brass band on tour and recruited musicians in Philadelphia as well as in Southern cities. Handy insisted that some Negro songs "drifted down the river" from Ohio to Louisiana.

Still, the first true jazz ensembles emerged in New Orleans. From this bustling, highly musical, culturally manifold, multilingual port came the first important jazz bandleaders, composers and soloists. They made their way to stations along the river and to nightclubs and recording studios, relaying their music across the nation and beyond its borders: Buddy Bolden, Freddie Keppard, King Oliver, Johnny Dodds, Lonnie Johnson, Baby Dodds, Sidney Bechet, Jelly Roll Morton, Louis Armstrong, not to mention the Original Dixieland Jazz Band, the jokey white band that was the first to record and popularize jazz as the soundtrack for a new era that would take its name from the new music, which the rest of the world spelled A-m-e-r-i-c-a.

It had to be New Orleans. Jazz is city music, born of saloons, dance halls, street parades, picnics, advertising wagons, funerals and parties. In an era when the South was almost entirely agricultural, New Orleans expanded as a lively metropolis with a distinctive architectural look, discrete neighborhoods, a level of sophistication associated with European capitals and a taste for pleasure. Many citizens spoke French and Spanish, and the city was infused with the culture of European Catholicism. While grand opera struggled to gain a foothold in New York and Boston, it thrived in New Orleans. Yet the same citizens who sponsored North American premieres of Rossini and Donizetti also celebrated Lent with the bacchanalian Mardi Gras.

The city's attitudes toward race also differed with general practices in Protestant North America. Elsewhere in the United States, slaves were forced to accept most aspects of Western society-though they were excepted from democracy and related constitutional rights. Slaves were required to learn English and become Christian, while overlooking fundamental ideas of Christianity that prohibit slavery in the first place. The goal was efficient interaction between slaves and masters. New Orleans, however, maintained a close connection to the slave trade in the Caribbean and South America, where the traffic in human beings was high-volume business, resulting in a profound retention of African languages, beliefs and customs. All this carried into New Orleans, where nearly half the population was black-enslaved or free.

By 1860, free blacks and Creoles of color had acquired civic power; some even participated in the slave trade. That changed abruptly with the rancor of Reconstruction: the imposition of Jim Crow laws; the Plessy v. Ferguson Supreme Court decision that essentially legalized segregation; the outbreak of lynching that so bloodied the soil not a thousand Katrinas could wash it clean. Even so, a despised minority, shunted aside into pockets of unimaginable poverty, created a cultural landscape made emblematic in music so vital that white newspapers editorialized against it even as white citizens rushed to hear and play it-and be reborn in it.

New Orleans changed my life, in 1963, when I visited as a boy and heard a band led by Emanuel Sayles with George Lewis. It wasn't just the music. The hotel had segregated toilets. The shop windows offered pickaninny dolls and slave-trade souvenirs. But the ballroom where this concert took place was integrated, welcoming, enlightened-an oasis of sanity and decency.

Years later, when I visited for research, I went to interview a member of the Zulu Krewe, who hosted a neighborhood barbecue that evening and insisted I eat, drink and meet practically everyone in the neighborhood, assuring me I was family. These are some of the people who didn't have means to heed the evacuation, people vilified by newscasters more horrified by looting than devastation-who condemn larceny but don't ask why the hospitals failed to clear out patients and newborns. This is the city that the president associates with his boozing days and the speaker of the house doesn't think needs to be rebuilt.

We are at war with terrorists, Iraqis, world opinion, nature and ourselves-and losing on every front.
You want to know about New Orleans? Play "Potato Head Blues." And shed another tear.