Common Elements.

Dances that require continuous repetition of a small set of steps have a tradition that precedes written history. Movement to a steady rhythm springs from an essential human desire that includes the need for exercise as well as for self-expression, and it is often associated with mating rituals. From the surviving evidence, we can see that many of the basic dance movements and formations remained more or less unchanged over many centuries. A variety of different formations were employed in dancing, the choice often having to do with the occasion and the space available. The formations, in turn, required different kinds of steps, and each dance was performed to a particular type of musical composition that matched the dance step and its speed. Changes in the dance movements coincided with changes in the phrases of the music. Although...