First, some bona fides. I know something about partying in the street. I’ve stumbled from Mardi Gras in New Orleans to têt in Saigon, poorams in Kerala, Colombo's Navam Maha Perahera, and the springtime water festivals in Yangon and Bangkok. I’ve felt the press of the crowd at saints’ days in the North End and the feast of Santa Lucia in her native Palermo, at the Fremont Solstice Parade and the WTO riots in Seattle.

After all of them and more, and after finally joining in February’s celebrations in Rio de Janeiro, I can attest: It’s true what they say. Carnaval in Rio is the greatest street party in the world. 

That’s not because of any of the amenities that attend it — not the music or the scenery in one of the world’s most musical and most beautiful cities, nor the astonishing floats and costumes that the samba schools flaunt in the enormous Sambodrome. That may be the world’s greatest parade (an elephant next to our mousy Seafair Parade), but it’s not a street party.

The real carnaval is what happens outside the Sambodrome, in neighborhoods rich and poor. And what makes it special is, at heart, its politics. Carnaval in Rio is the ultimate leveler, an irrepressible expression of class-crossing populist sentiment that defies every attempt to suppress, co-opt, and subvert it.

The Sambodrome parades are a marvel of organization and creative vision. Down in the streets, however, a marvel of disorganization — or rather, of dispersed, spontaneous self-organization by hundreds of self-formed, neighborhood-based groups called blocos — unfolds. The blocos swarm like ants, parading down the narrow streets and broad avenues for hours, with revelers — loyal fans and casual tag-alongs — thronging behind.

Their names compose a ribald distillation of carioca culture, and a cheeky dialogue: Céu na Terra (Heaven on Earth), Suvaco do Cristo (Christ's Armpit), Simpatia É Quase Amor (Sympathy is Almost Love), Que Merda É Essa? (What Shit Is This?), É Pequeno Mas Vai Crescer (It’s Small but It’ll Grow), Meu Bem, Volto Já (My Dear, I’m Coming Back), Volta, Alice! (Come Back, Alice!), and finally, Voltar pra Que? (Come Back for What?).

Carnaval’s good humor shows in its costumes. Satire and self-mockery are everywhere: One young woman toured with an impeccable replica of the street signs for a Copacabana junction where prostitutes supposedly abound — and above it that iconic Brazilian image, a row of tanga-clad (i.e., virtually unclad) female bottoms splayed on the beach. Another held her baby, both dressed in black-and-white prison stripes, and a sign: “Prisoner for life.”

Centurions menaced tonsured friars with plastic swords, but machismo was generally missing; instead, a disheveled sort of cross-dressing (wigs, bras, and three-day whiskers) prevailed, as it has for decades. I saw several women decked out as cops, but no men; the guys were all preening in shabby drag and a few days’ stubble.

Likewise blessedly absent: the morbidity that pervades when Americans costume themselves for Halloween or any other occasion. I saw one or two Death figures, many merry widows in filmy weeds, and one clovis who, true to tradition, scared the kids — but nary a zombie or vampire. This despite the fact that Brazil receives the same teen horror movies as America. If zombie mania signals American decay, does its absence betoken BRIC-era optimism?

Of course beer saturates the proceedings, even more than it does daily leisure in Brazil; it starts flowing when the blocos do, in the morning, and never stops. Vendors are everywhere, hawking cans of Antarctica from imposing carts, battered Styrofoam coolers, and everything between. Even on the street, in Rio’s sweltering summer, the beer must be stupefyingly cold — estupidamente gelada — or forget it. There is no sight more forlorn than a vendor whose ice has melted and whose beer has gotten warm, watching the best money of the year pass her by. According to one improbable published report, 70 percent of Brazil’s beer sales occur during Carnaval. I don’t believe it, but the fact that anyone would even repeat such a claim says something.

All of it is perfectly legal, of course. It is at first unnerving, then liberating, then just the way things are to be able to drink on the street, in the subway, everywhere. Up here, that would be a prescription for brawling, stumbling chaos.

There is of course ample violence in Rio — more than 2,000 officially reported homicides a year and at least twice as many actual killings. But it’s sober violence, committed for a purpose, however ghastly: robbery, fights over drug turf, vigilante “street-cleaning” by moonlighting cops. Not random venting.

In three days and a night of chasing the blocos along with tens of thousands of people, many if not most of them likewise drinking from morning on, I never saw anyone conspicuously drunk, nor one — one — display of rude, surly, or pushy, much less violent, behavior. Can you imagine Seattleites behaving so well while drinking freely at any event, much less on Fat Tuesday? Even the February chill hasn’t stopped them from shtupping in the street and beating each other to death in Pioneer Square.

Still, it’s not fair to compare our winter bar crawl with Rio’s week-long midsummer carnaval. The fairer comparison would be Seattle’s month-long, citywide summer festival, Seafair, which like carnaval includes a mainstage parade and lots of neighborhood parties. But consider the differences, aside from Rio’s obvious advantages of scale.

Seafair’s defenders insist that, however cheesy it may be, it’s the authentic, populist, pre-glam expression Seattle. But Seafair, like so many other Seattle milestones and traditions, is actually a boosterish contrivance: In 1948, a few business swells tooling around Lake Washington on car dealer William O. McKay’s Elco cruiser decided the town needed a summertime shot in the arm. Fiat Seafair.

The Torchlight Parade — excuse me, the Alaska Airlines Seafair Torchlight Parade Presented by AT&T & LG — is shamelessly promotional. Amidst the drill teams and school bands, local dignitaries from Drew Carey to the mayor do the pope-style ride-and-wave. If you’re not in the show, you sit docile on the sidelines. Even those scruffed-up pirates are an elite, self-perpetuating fraternity, with license to behave in ways no one else can and no other adult would want to.

Yes, I know, they and the Seafair Clowns raise charity money and go around entertaining children in the hospitals. If I were an ailing child I’d say, "Send in the clowns — and hang the pirates from the yardarms."

I saw scores of celebrants, mostly women, dressed as pirates in Rio, and none felt obliged to act like a lout. Down there, anyone with a funny hat and eyepatch can be a pirate, and anyone at all can join the parade. Rio could call in military seapower and airpower and jetboat hydrocarbon power to beef up its celebration, as Seafair does (though I’d hate to be a Blue Angel threading through Rio’s vertical terrain). But Brazilians don’t want all that.

Their memories of military dictatorship still smart 27 years after it ended. And they know that the only show of power carnaval needs is people power.

That’s the essential difference. Carnaval (the “lifting of the flesh”) is no boosterish invention. It rose from the social depths, in Europe and again in the Americas, as an eruption of defiant exuberance among the 99 percent, who were obliged to be meek and deferential the other 99 percent of the year. It resonates especially in Brazil, the destination for most of the slaves abducted from Africa, which the World Bank more than 20 years ago found had the most yawning income disparities of all the countries it surveyed.