Growing up in Atlanta, Georgia, Andres Juliao did not have much opportunity to hear the accordion. It was only when he visited his family in Barranquilla that he came to appreciate the sound that is the backbone of vallenato, one of the many traditional musical genres of Colombia's Atlantic coast. He began studying the accordion four years ago. Two years later he rounded up a number of veteran Colombian folklore musicians living in Miami to form his own vallenato group here featuring singer Poti Lozana, Tayrol Carrillo on caja or box, Leo Ceballos on guacharaca, Francisco Prieto on bass, Mario Lozano on congas, and Hermides Benitez on timbales. Andres Juliao and his Vallenatos also play cumbia and contemporary vallenato-pop, but the accordionist says he still prefers classics such as "La Gota Fria." Carlos Vives, who made "La Gota Fria" an international hit, has been known to sit in at gigs around town, but even without the charismatic star, this exuberant ensemble more than holds its own.