“I went to Cuba two years ago, and it is no longer there. Danzon is dying out. They only dance salsa,” Carranza said.

In an essay on the musical form, Ceron wrote that the elegant swing dance “has the particular characteristic that … after each refrain, the woman fans her face and the man wipes the sweat from his brow, wooing each other as they do so.”

In the early years, the dance had a whiff of iniquity, made stronger by a historical incident. On the night of Nov. 18, 1901, during the rule of dictator Porfirio Diaz, police raided a house in which they found 41 men, 19 of them dressed as women. The raid is said to have occurred just as a danzon was being played.

A rumor at the time said Diaz’s son-in-law was among the upper-class men present. To this day, “41” remains a symbol in Mexico of taboo. Some high-rises don’t have a floor 41, and it’s rare to find a house along a street numbered 41.

By the 1920s, after Mexico’s revolution, times had changed, and ballroom salons opened in the capital, bringing a true explosion of danzon, especially in the city’s premier venue, Salon Mexico, where throngs lined up to enter its multiple ballrooms. Cuban and Mexican musicians filled the dance halls.

Benjamin Muratalla, deputy director of the Fonoteca, a national archive of popular music and street sounds in Mexico, said the danzon incorporates many elements of African culture along with its European roots.

“Danzon has a big dose of black cultures — its sensuality, its elegance, that snappy tropical rhythm all come from there,” Muratalla said.

Mexican musicians began to add their own elements to danzon, and the physical movements varied. Unlike Cuban dancers, who embrace one another more closely, Mexican dancers move at greater distance and with more delicacy.

Victims of economic change, ballrooms began to close down in the 1970s and 1980s as families stayed home or chose other entertainment options. But a movie, Danzon, in 1991 helped the dance revive, telling the story of a telephone operator who lived for her work, her daughter and danzon in the Salon Colonia ballroom.

Some experts see danzon inevitably falling by the wayside, ignored by youth wearing ear buds, exposed to MTV and oblivious to the rhythms of Mexico’s past.

“Unfortunately, new generations imbued with other types and genres of music don’t know this music. They think that it’s only for their grandparents and old people,” Muratalla said.

Some better-educated young Mexicans, though, embrace what they can find of traditional culture, from the drinking of mescal (a distilled alcohol made from the maguey plant) to traditional forms of music. One of the better danzonera bands is La Playa, comprised mainly of younger musicians, Ceron said

Still, without ballrooms to support them, probably fewer than 40 professional danzon bands remain, he said, and few are composing new songs with contemporary themes.

“They keep playing the same 50 songs we’ve always heard,” Ceron said.

“If the danzon groups go by the wayside, then danzon is over,” he added.