In it's traditional form, Merengue is played on accordion, saxophone, 
box bass with metal plucked keys, a guayano (a metal scraper 
-transformed from a kitchen implement), and a two ended tambora drum, 
struck with hand and stick. It's rural music with close affinities to 
Haitian meringue - though the latter, sung in Creole, tends to have a 
slower, more nostalgic sound, based on guitar rather than accordion. 

   In the Dominican Republic, Merengue experienced something of a golden 
age during the dictatorship of Rafael Trujillo, who held power from 
the 1930s until his assassination in 1961. Trujillo was from peasant 
roots and he promoted the music as a symbol of national expression and 
the culture of the former underclass. He constrained its traditional 
role as a music of social commentary but provided a forum for the 
musicians in the dancehalls. Larger Merengue orchestras were 
developed, with piano and brass to cater these new urban audiences. 

   More often, though, these days Merengue comes as big-band, salsa 
-cousin dance music, employing hi-tech instruments. The sound was 
developed from the 1960s on, notably by Johnny Ventura, as the 
country opened its ears to North American influences - and to the 
salsa that was being forged all across the Caribbean. 

   The biggest change to the sound came through boosting the saxophones 
role, either in overdubbing in the studio or lining up players on 
stage, which gives the music a sharp, stuttering momentum that the old 
style only hinted at. The other significant break has been in 
replacing the accordion with electric guitar, keyboards and 
synthesizers, or occasionally sampling it, like a goast memory. 
Despite the change of instruments, the rhythm of Merengue has changed 
very little, and remains unmistakable, even in the radical versions by 
singer-songwriter Juan Luis Guerra, the star of the moment. The 
tambora keeps a fast pulse going, working around conga patterns, while 
the bass drum, operated with a foot pedal, provides a monotonous 
thumping 1-2-3-4 beat. 
 

Source: "World Music. The rough guide.", Rough Guides Ltd., London 1994. 
Modified by: Julio Peralta