They happen most Sundays here between Labor Day and mid-December, though you have to hunt them down. For the city's blacks, second-line parades are spectacular parties that tie communities together.
At a time when popular music has become a disposable commodity these celebrations are also a reminder that music originally served a higher purpose. I was in two parades here recently and saw that clearly.
Powered by ultrafunky brass bands, armies of revelers danced their way down the city's side streets, their numbers swelling with each block. Trumpets growled, trombones moaned and saxophones wailed over the popcorn-popping rhythms of the snare, bass drum and tuba.
But it was the people behind the band -- the second line, where I was -- who stole my heart. Attacking wine bottles with sticks, tapping out intricate cross rhythms, blowing whistles or honking horns on the off beats, they added their own layer of chattering syncopation.
And in the sticky heat the music lifted people out of themselves. A middle-aged woman danced alone, convulsed in ecstasy. A man climbed 20 feet up a nearby telephone pole and shook, as if with palsy, to the shuddering rhythms of a hoarse-voiced chorus below.
Parades such as this go back more than two centuries, when slaves kept their African heritage alive by drumming and dancing and singing. Later, in the 19th century, black brass bands would lay down the beginnings of jazz in parades sponsored by social aid and pleasure clubs. Those parades were, and still are, freedom marches.
But in the rest of America? The production of music is a multibillion-dollar mass-pop culture created and sustained by media and entertainment conglomerates. And like their counterparts in professional sports, film and television, record companies not only meet demand but shape it.
Turn on the radio in Kansas and it's indistinguishable from radio in Maine or Alabama. Or flip on MTV, where music is used to create markets and hype films, and you might believe for a moment that you're part of a community that's the same everywhere.
Maybe in the 1950s and 1960s rock-and-roll provided a sense of community for a fragmented youth culture. But the music that was once so liberating and different from one city to the next now sounds like it was put together by market-research teams. And the calculated performance on records and videos becomes more important than the live performance, the celebration.
What accounts for this difference in outlook in New Orleans? Centuries of relative isolation and an Afro-European population that didn't speak English through much of its history.
There is also a willingness to absorb musical styles, a forced economic and cultural self-sufficiency and a history of race mixing that has gone on despite deep-rooted discrimination.
Ages before Western psychiatrists prescribed mind-altering drugs, shamans exorcised demons and disease with magical rhythms played on drums and rattles. David sang ethereal songs in the desert so he might see God. That's always been the chief purpose of music: transcendence and healing.
Rock got caught up in placing the emphasis on shattering everything that came before it: on alienating one generation from the next. But in New Orleans, children play in bands with their fathers, and musical bridges are built across the generations.
JORY FARR is a music critic and columnist for the Press-Enterprise in Riverside, Calif.