ALL OVER THE WORLD, salsa dance classes are transforming non-Latino locals from wallflowers to exhibition hancers. For "authentic" Latin American teachers, the prospect of teaching gringos to dance salsa is no longer the frustrating chore it was a decade ago. National differences create healthy rivalry, but New Yorker Eddie Torres, the professor of salsa dance, says: "It doesn't matter which style you dance, weather you start on the first beat - dancing "on the one" (like the Cubans and Colombians) - or on the second - dancing "on the two" (like the Latin New Yorkers, Puerto Ricans and the ballroom set) - as long you're consistent and understand which beat you're on.

The beat you choose to kick you off across the floor identifies your dance nationality as closely as your Spanish accent. New York salsa, Dominican meringue and Colombian cumbias have a consistent beat running through, whereas Cuba's new salsa timba changes rhythm within a song and the dancers change with it. Wherever you are, certain basic apply.