Merengue is the national music of the Dominican Republic, developed as accompaniment to the folk dance of the same name as far back as the mid-19th century. In its traditional form -- known as merengue tipico -- merengue was a vocal-driven dance music that reflected the blending of Spanish and African cultural influences. The accordion was used as the lead instrument, and the guitar frequently provided accompaniment; the most important percussion instruments were the tambora drum and guiro (scraper), with the marimba often joining that basic combination. Merengue pieces usually consisted of a paseo (introduction), then a theme introduced by one or two vocalists, and then a more uptempo call-and-response section featuring a vocal soloist and chorus. It was strongly similar to a Haitian dance form referred to as "méringue," and the exact origins are widely debated, with any distinctions largely resting on geographic location. Merengue had been the music of rural peasants until dictator Rafael Trujillo, in deference to his roots in that social class, declared it the official national style in the mid-'30s; its popularity spread rapidly as peasants emigrated to cities and brought the style into urban dance halls, although the upper classes were a bit slower to accept its legitimacy. Over the next three decades, merengue ensembles grew into large orchestras complete with piano, brass, bass, and saxophones; the saxophone gradually supplanted the accordion as the lead instrument of choice. By the 1960s, led by performers like Johnny Ventura, merengue was usually performed in big-band formats very similar to salsa, although merengue's rhythms and accompanying dance movements were not as complex (and, therefore, easier for Latin-dance newcomers to learn). Electric guitars and synthesizers were introduced over the years and became standard instrumentation, rendering the accordion all but extinct as an important part of the music. Merengue's dominant figure in the late '80s and early '90s was African-influenced singer/songwriter Juan Luis Guerra, whose 1990 album Bachata Rosa fused merengue with a similar, guitar-based rural style called bachata, helping bring that music into the Dominican mainstream. Merengue became quite popular outside of the Dominican Republic as well, finding especially strong footholds in Puerto Rico, New York, and Miami.