Ternary Form (ABA form)	Theory Things   William Wieland
Sectional or Closed Ternary
Both A B A and A B A' are common. Da capo arias are in ternary form. Sectional or closed ternary means that the A section begins and ends in tonic. In a continuous or open ternary form, the first A section would not end on tonic. B often ends on V. B contrasts with A melodically, harmonically and/or texturally. B may develop motives or themes from A. Repeat signs may occur, frequently   ||: A :||: B   A :|| Though A A' A'' and A B C each include three sections, A A' A'' features no contrasting middle section and A B C does not recapitulate the opening material. Compound ternary is a three-part form in which each section is itself a binary or ternary form.