period (music)

A period is a phrase consisting usually of an antecedent and consequent and totaling about 8 measures in length (though this varies depending on meter and tempo). Generally, the antecedent ends in a half cadence while the consequent ends in an authentic cadence. Frequently, the consequent strongly parallels the antecedent, even sharing most of the material save the final measures. In other cases, the consequent may differ greatly (for example, the period in the beginning of the second movement of the Pathetique Sonata).
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