Symmetrical Periods: Symmetrical periods are musical phrases with equal lengths for their antecedent and consequent parts. They provide balance and predictability in music.
Phrase Structure: Phrase structure refers to how musical ideas are organized into smaller units called phrases. These phrases can be symmetrical or asymmetrical, contributing to the overall structure of a piece.
Cadence: A cadence is a musical progression that marks the end of a phrase or section. It provides a sense of resolution and closure. The placement of cadences can be influenced by the symmetry or asymmetry of the surrounding musical material.