BUENOS AIRES — Daniel Frago sat with a cup of coffee at a small table on the edge of the dance floor, explaining the art of the tango.
"It's not about the man and the woman," the 55-year-old Buenos Aires hairdresser said. "It's about the driver and the driven."
Frago had come out to celebrate the eighth birthday of Tango Queer, a weekly party where women dance freely with women, and men dance freely with men.
It's one of several popular gatherings in Buenos Aires that cater to gay and lesbian tango enthusiasts, as well as straights who want to test the dance's traditionally heterosexual gender roles.
Here there are no expectations that a dominant man lead and a passive woman follow, said organizer Mariana Docampo. "Everyone can dance the role they want with the partner they want."
Docampo founded Tango Queer in 2005, a few years after a friend started his own gay tango salon. A professor of literature and an accomplished dancer who had studied tango for years, she was tired of following her male partner's moves. And besides, she said, "I wanted to dance with women."
Parties like hers have popped up in cities across the world, including San Francisco, Seattle and Stockholm. Similar festivals have been held in New York, Hamburg and Berlin.
Docampo's salon unfolds in a second-story nightclub in the brick-paved neighborhood of San Telmo, which has been home to tango for 150 years. First danced among poor European and African immigrants in bars and brothels, it later caught on with the upper classes and found its way to cities such as New York and Paris.
Tango has been called the world's most sensual dance, and it can appear deceptively simple: Two partners, tightly wound, walking together around a dance floor. But there are no set steps, and many dancers say it takes years or even decades of practice to learn the subtle gestures that communicate where the dance is going next.
Docampo's night begins with an optional lesson. On this evening, about 20 couples were crowded onto the brightly lighted floor, carefully mimicking a step she had just introduced. Docampo, who has a dancer's posture and a mass of black curls, stood watching with her hands on her hips.
"You don't need so much space between you," she called out to two men. And to a male-female pair: "Don't bend your legs." She tapped her shoulders twice and explained: "It's all up here."
The class attracted locals with years of experience as well as first-timers from faraway places like Poland and Spain. A male couple on vacation from the United States nodded at a less proficient pair. "We're better than them," one of them said, loud enough to be heard.
Docampo's party has benefited from a revival of interest in tango among younger Argentines as well as her city's growing reputation as a capital of gay tourism.
Argentina legalized same-sex marriage in 2010 and Buenos Aires now boasts hostels, tour companies and apartment rental services geared to gay travelers. The Axel, a boutique hotel with a glass-bottomed pool and complimentary condoms, describes itself as "hetero-friendly."
For Docampo, it's fitting that a dance that originated on the fringes of society is now being embraced by the gay community. She pointed out that in the early days of tango, men practiced their moves with other men before venturing out to the salon to ask women to dance.
A little before midnight — things start late in Buenos Aires — a traditional tango orchestra took the stage with a piano, violins and three accordions.
The floor quickly filled with dancers. One woman extended her hand to another and asked, "Do you want to drive?"
From the sidelines, Lilian Ivachow watched with a glass of Malbec. A film critic who has tangoed for more than 15 years, she started coming to Tango Queer a few months ago to learn how to lead.
"If you want to be a good dancer, you have to know the two roles," she explained.
She has found, to her surprise, that she prefers the role traditionally danced by men. "The male role is more active, it's more creative," said Ivachow, 42. "It propels the dance."
There's also less incentive to wear uncomfortable high heels, she said. On this night, she wore black tights and a pair of combat-style boots.
For Frago, the hairdresser, both the male and female roles have appeal. He started dancing only a few months ago, after a boyfriend invited him to Tango Queer. The relationship didn't last, but his love of the dance did.
"It conquers some people," he explained. "It conquered me."