Cumbia, vallenato and gaita are Colombian music and dance forms. Cumbia is the principal style of the Atlantic coast. Gaita (originally the double-reed flute used in traditional flute-and-drum cumbia ensembles) is a sub-genre of cumbia. During the 1940s and '50s, cumbia, gaita, porro (a variant of cumbia) and other folkloric styles merged into the urban dance band style known as música tropical (literally, "tropical music"). Prominent bandleaders of the música tropical movement were Lucho Bermúdez and Pacho Galán. The emergence of a simplified variant of música tropical called raspa in the 1960s and the popularity of recordings by raspa bands like Sonora Dinamita spread the simplified style to Mexico, Central America, Ecuador, Bolivia and Chile, establishing the basis for local cumbia traditions. Vallenato (literally meaning "born in the valley") is a cumbia / música tropical variant performed by small accordion-based ensembles that replaced the big band sound in the '70s. Chicha music refers to Peruvian Cumbia. - John Child