Ternary form

Ternary Form is a form used to structure compositions. The form is comprised of three sections (ABA). The form was often used from the classical period onward as the basis for marches, minuets, scherzos, and independent works.

Ternary vs. Binary

Ternary form could be considered a more structured version of Binary form for a number of reasons. While in Binary form, it was customary to repeat the first section (giving a structure of ABA'); in ternary form, it is customary to repeat the first section and then recapitulate it at the end (giving the structure of AA'BA). Harmonically, Ternary form is different from Binary in that instead of ending the first section in the dominant one can end it in the tonic - thereby making the first section wholly independent. The other difference comes in the pitting of sections to each other. In binary form, the sections are meant to compliment each other. Often times, the material in the sections was related thematically. In ternary form, the sections are meant to contrast/conflict one another. For unification, however, it is still important when composing these forms to link the two ideas in some appropriate manner.

Types of Ternary Forms

Ternary form has two distinct types simple ternary (ABA) and compound ternary (ABACDCABA).

Simple Ternary

In simple ternary form, the first and third parts (A) are musically identical, or very nearly so, while the second part (B) contrasts sharply with it. The B section is often known as a trio. The middle section will generally be in a different key, often the dominant of the first section (a perfect fifth above). It usually also has a contrasting character; in a march, for example, the highly rhythmic and strident character of the march itself is usually contrasted with a more lyrical and flowing trio. Often the trio is in a 3/4 time signature as opposed to the 4/4 of the primary march theme.

Compound Ternary

In compound ternary form, each section is itself a ternary or binary.

As seen in the above picture, each section is a ternary. The first and third sections are identical, whereas the middle section is different. One can even compound each section even more by making the smaller sections inside each section ternary as well.

Expansion

Sonata-Allegro form has sometimes been considered an expanded category of ternary form, with its three sections of exposition, development, and recapitulation. While this is possibly one contender for its ancestor, Binary form itself is often seen as the first step towards the form.

Examples

The repertoire is chock full of ternary forms, from symphony to string quartet to ballet.

• Piano Concerto No.21 (K.467) 2nd Movement - Wolfgang Amadeus Mozart
• Rondeau - Mouret
• Symphony no 9, 2nd Movement - Antonin Dvorak

References

-Britannica Encyclopedia [www.britannica.com/EBchecked/topic/588055/ternary-form]

-Essentials of Music [www.essentialsofmusic.com/glossary/t.html]

-Wikipedia [en.wikipedia.org/wiki/Ternary_form]