(averill) in rumba, you have a clave. the clave pattern is the key to the rhythmic structure of the ensemble. in rumba guaguanco the clave sounds like this: [claps] the first side, if you divide this pattern in half, has three beats. and the second half has two beats. and this is an asymmetric pattern and its asymmetry is critical to the sound of the entire ensemble. the musicians have to take this key and relate their drumbeats to this fundamental pattern th structures the entire musical ensemble. african musics and afro-caribbean music have had a profound influence on pop musics throughout the world... notably in the development of the rhythm section. african-american musicians, who were marching in the early brass bands in new orleans used bass drums, snare drums, cymbals-- put them together into a repeating rhythmic unit. and later on, when this music moves indoors, musicians put these together into a single set--the drum set. [band playing dixieland] the drum set and the bass are called the rhythm unit in a band and