Antecedent Phrase: The antecedent phrase comes before the consequent and sets up the musical idea or "asks" the question.
Period: A period is a two-part musical form consisting of an antecedent and consequent phrase. It creates balance and symmetry in music.
Motive: A motive is a short melodic or rhythmic idea that can be developed throughout a piece of music. It often appears in both antecedent and consequent phrases.