Form
Binary and Ternary Form: Dance Patterns to Art Music
Simple and rounded binary, ABA and da capo: the cadence plans that define each section and how dances grew into art forms.
Ternary form
A three-part ABA form in which a contrasting middle section is framed by a return of the opening material, usually in the tonic.
Also called: ABA form, Three-part form
Ternary form is a three-part structure, ABA, in which a contrasting middle section B is framed by a return of the opening A. The return is usually in the tonic, and the middle section may be in a related key, such as the dominant in a major-key piece or the relative major in a minor-key piece. The da capo aria is a Baroque instance: a vocal ABA form in which the A is sung again from the beginning, with added ornamentation. Ternary form balances stability and contrast. A piece in C major might have A in C, B in G or F, and return to C for the last A. Each section can be expanded, but the form depends on the return of A.
Related terms
- Binary formA two-part form, AB or AABB, in which each part is usually repeated and the first part moves from the tonic toward the dominant.
- RondoA form built on a main theme that returns between contrasting episodes, typically in the pattern ABACA or ABACABA.
- Sonata formThe form of many first movements: an exposition of two contrasting themes, a development, and a recapitulation that returns both themes in the tonic.
- Theme and variationsA form in which a theme is stated and then altered in successive variations, keeping its harmonic or melodic outline while changing texture and character.