the two-side. The two sides of clave cycle in a type of repeating call and response. [With] clave . . . the two bars are not at odds, but rather, they are balanced opposites like positive and negative, expansive and contractive or the poles of a magnet. As the pattern is repeated, an alternation from one polarity to the other takes place creating pulse and rhythmic drive. Were the pattern to be suddenly reversed, the rhythm would be destroyed as in a reversing of one magnet within a series . . . the patterns are held in place according to both the internal relationships between the drums and their relationship with clave . . . Should the drums fall out of clave (and in contemporary practice they sometimes do) the internal momentum of the rhythm will be dissipated and perhaps even broken—Amira and Cornelius (1992). An actual key pattern does not need to be played in order for a key pattern to define the period. See also Section (music) Sentence (music) Sources External links Slideshow about musical periods by the San Francisco Conservatory of Music Formal sections in music analysis