MIAMI (Reuters) - You have to sign a release form accepting that your instructor may hold you close, touch you and invade your personal space.

But apart from that American touch, when the bellows instrument known as a bandoneon sets off a wistful tango, you might just as well be in Buenos Aires.

(Reuters Photo) A couple dance the tango at a tango school in Miami May 26, 2005. Tango 'milongas', as they are called, are booming in Miami, the heavily Hispanic city better known for salsa and other Latin rhythms. Dozens of people meet until 2 or 3 a.m. on any night of the week to move sensually to the rhythm of the Argentine music, born in the late 19th century in the grittier neighborhoods of Buenos Aires. (Carlos Barria/Reuters)

Tango classes and ballrooms -- milongas, as they are called -- are booming in Miami, the heavily Hispanic city better known for salsa and other Latin rhythms.

Dozens of people meet until 2 or 3 a.m. on any night of the week, to move sensually to the rhythm of the Argentine music, born in the late 19th century in the grittier neighborhoods of Buenos Aires.

"Do these people know each other?" asks Linda, a tourist from Minnesota, startled by the couples gliding across the dance floor, their bodies almost fused.

Tango is certainly not for the physically shy.

"That's what's so great about it. You can be with a total stranger, make that passionate dance together and then just walk away," says Carol Durbin, a Miami Beach native who has been dancing tango for the last year.

The return of the show Tango Argentino to Broadway in 1999-2000 gave the Argentine dance a boost, and milongas mushroomed in the United States.

Tango has its fans not only in Latin cities like Miami -- which even hosted a "tango congress" this month, or in big cosmopolitan areas like New York and Los Angeles, but in unexpected places like Kansas City, Albuquerque, Boston or Washington.

For many men, the milongas can be a great place to meet women, who show up in plunging necklines and slit skirts.

"You can meet women of all ages and all nationalities. Some are really hot," says Roberto, a 53-year-old regular at Sunday's milonga in Hallandale Cultural Community Center. "In those cases you might want to try a dance or two to see if there's chemistry."

But even if Argentines call it "the vertical expression of a horizontal desire," the tango can remain just a dance.

"There might be men looking to make a move on a woman, but it is generally accepted in the community that you are there just for the dance," says Durbin.

BEING "PARKED": NOT FUN

Whether in Buenos Aires or Miami, the tango community can be unforgiving: if a woman can't dance, no matter how sexy she is, she will probably be "parked" after the first two dances for the rest of the night.

The bad male dancers take a bit longer to weed out, since they can keep on asking. In Argentina, this is done with a subtle nod -- to spare the embarrassment of rejection.

The milonga is not a place where women ask men to dance. Neither should a woman seek control on the floor, where to tango well is to know how to let go.

"The men have to learn how to structure the dance; the women, apart from recognizing the man's leads for the different moves, have to learn to surrender," says Roxana Garber, who owns a small studio on Miami's Calle Ocho with her husband and dance partner, Oscar Caballero.

To the uninformed, tango seems to be about legs intertwining and feet floating above the dance floor. But old time dancers say there's no tango without an expert embrace.

"It all starts with the chest. The man actually leads with his chest and then, by pressing different parts of her back with his right hand he tells her how to move her legs," says Caballero.

There is a basic set of steps that any beginner will be taught to follow, but it is pointless to memorize all the moves. Tango about feeling the partner's body, which is why most women dance with their eyes closed, looking to connect with their partners and enter "the zone."

"TANGO HEAVEN": WHERE YOU WANT TO BE

"I call it tango Heaven. It's when you just forget about the steps. It's like being beyond time and space ... you are into the music, being carried away," says Dianne Castro, a Miami native who has been dancing Latin rhythms most of her life but has discovered tango only recently.

At Randy Pittman's ballroom on Calle Ocho, only Saturday is tango night. The rest of the week his place hosts salsa, merengue and cha-cha, echoing Miami's multicultural community, where most of the dancers get to tango only after having learned other Latin rhythms.

"Tango is about seducing, slowly luring your partner. I find salsa much more animalistic, ritualistic, you're almost waiting for the fire to start blazing," says Durbin.

Magdalena Morales, a Puerto Rican who excels at tango but also at salsa and merengue, is one of the most sought-after partners at Randy's. She is in her 50s and her military-short platinum hair and dramatically made-up eyes scream "tango."

"Once you are into it, you can't get out. Tango gets under your skin," she says, walking back to the dance floor on her glittering high heels.