Ternary form, sometimes called song form, is a three-part musical form, usually schematized as A–B–A. The first and third parts (A) are musically identical, or very nearly so, while the second part (B) in some way provides a contrast with them. Examples include Schumann's "Folk Song", Album for the Young (Op. 68, No. 9), the de capo aria "Vo' far guerra, e vincer voglio" from Handel's Rinaldo, and Chopin's Prelude in D-Flat Major (Op. 28).
In ternary form, unlike the rounded binary form, each section will usually be self-contained both thematically and tonally (that is, each section contains distinct and complete themes, and ends with an authentic cadence. The B section is generally in a contrasting but closely related key, usually a perfect fifth above or the parallel minor of the home key of the A section (V or iii). It usually also has a contrasting character; for example section A might be stiff and formal while the contrasting B section would be melodious and flowing.
A distinction is sometimes made[by whom?] between "compound ternary form" – in which each large part of the form is itself divided in a way to suggest ternary or binary form (giving, for example, an overall scheme of A–B–A–C–D–C–A–B–A) – and "simple ternary form", in which each large part of the form has no particular structure itself.
Da capo arias are usually in simple ternary form; minuets (or scherzos) and trios are normally compound [(1A–1A–1B–1B) (2A–2A-2B-2B) (1A-1B)] where the second section (C-D-C) is often called the trio, especially in minuets and scherzi.. Another name for the latter is "composite ternary form".
The repetition of any section results in expanded ternary form.
Commonly, the third section will feature more ornamentation than the first section (as is often the case with da capo arias). In these cases the last section is sometimes labeled A’ or A1 to indicate that it is slightly different from the first A section.
As well as in marches, ternary form is often found in baroque opera arias (the da capo aria) and in many dance forms, such as polkas. It is also the form used in the minuet (or scherzo) and trio, which, in the Classical era, was usually the third movement of symphonies, string quartets, sonatas and similar works.
- "Binary and ternary form" in the Harvard Dictionary of Music, 2nd ed. rev. and enlarged (1969). Willi Apel, ed. Cambridge, Mass.: The Belknap Press of Harvard University Press
- White, John D. (1976). The Analysis of Music, pp. 53–54. ISBN 0-13-033233-X.
- See "Trio (2)" in the Harvard Dictionary of Music, 2nd ed. rev. and enlarged (1969). Willi Apel, ed. Cambridge, Mass.: The Belknap Press of Harvard University Press
- Benward & Saker (2003). Music: In Theory and Practice, Vol. I, p. 315. Seventh Edition. ISBN 978-0-07-294262-0.
- Small Ternary Form www.artofcomposing.com