COMMON FORMS

Common forms are certain forms that proved successful through music history. Composers use them as templates for forms of their compositions. However, there are no strict rules and numerous variations of these forms do occur in practice.

Strophic form

A strophic form is a form consisting of two or more structural units which are called stanzas and are made of the same material. 

The outline of this form is A A A…

Binary form

A binary form (or two-part form) is a form consisting of two structural units that are called parts and are made of different material.

The outline of this form is A B. The parts are often repeated, for instance ‖: A :‖: B :‖. Usually, we can find both some contrasts and some similarities between the materials of the parts.

A binary form can be sectional or continuous. A sectional binary form has part A which is harmonically closed. That is, part A ends with the authentic cadence in the same key in which it begins. A continuous binary form is a binary form that is not sectional.

A binary form can be rounded or simple. In a rounded binary form, near the end of part B, the material from part A returns. A simple binary form is a binary form that is not rounded.

Often, part A modulates from the home key to its dominant key (or when the home key is a minor key, from the home key to its relative major key) while part B modulates back to the home key.

Movements in a Baroque suite are usually dances that have a binary form. The next figure shows Bach’s Bourrée from Partita for Violin Solo No. 1 in B minor, BWV 1002. Bourrée is a dance of French origin. Unlike the other examples in this book, this one is not written for the piano solo. It is a beautiful composition written for the violin solo. It consists of shorter part A and longer part B. Both parts are repeated. Thus, its outline is 

‖: A :‖: B :‖. 

You can click on the structural units in the outline to hear them on YouTube. Part A begins in the B minor key and modulates to the D major key (the relative key of the B minor key). Part B begins in the D major key and modulates back to the B minor key. Thus, it has continuous binary form. Also, near the end of part B, the material from part A returns. Only a few measures from the beginning of part A occur again, slightly modified but still very recognizable. Thus, it has rounded binary form.

Figure: An example of continuous, rounded binary form: Bach’s Bourrée from Partita for Violin Solo No. 1 in B minor, BWV 1002

Ternary form

A ternary form (or three-part form) is a form consisting of three structural units that are called parts and the first and third of them are made of the same or similar material while the second one is made of a different material. Thus, it is based on the principle of the return of a material. 

The outline of this form is A B A. The parts can be repeated. The contrast between the sections A and B is usually greater than in the binary form so we often speak about the contrasting B section.  

Often, the first and third parts are in the home key, while the second part is in the home key’s dominant key (or when the home key is a minor key, the second part may be in the home key’s relative major key). 

When a ternary form is long enough, auxiliary structural units like transitions or a coda can appear. The example is Brahms Intermezzo in Bb major Op. 117 No. 2. It has a ternary form. The parts are not repeated. There is a transition between part B and return of part A and there is a coda at the end. In its return, part A is significantly changed (but still easily recognizable) so we can also label them A1 and A2. The coda begins with the material similar to part B. However, it is very clear that its role is to finish the composition.  The outline is 

A B Transition A Coda.

You can click on the structural units in the outline to hear them on YouTube.

Distinguishing between rounded binary form and ternary form

Sometimes, it is hard to distinguish between the rounded binary form and ternary form. In both cases, material from part A returns. Most often, when only a fragment of part A returns, this indicates the rounded binary form. When whole part A returns, this indicates the ternary form. However, exceptions exist. For instance, the next figure shows Schumann’s Norse Song from Album for the Young Op. 68 No. 41.

For this composition, it is not easy to determine whether it is the rounded binary form or ternary form. Part A begins with measure 1 and ends with measure 8. Whole part A returns in the measures 13 to 20. When part A returns, melody is the same, but there are some variations in harmony and texture. However, it is obvious that part A returned. The return of whole part A might lead us to conclude that this is a ternary form with the outline A ||: B A :||. However, then part B would not have enough contrast and would be too short, relative to part A. This lack of contrast can be seen well in measure 9 where the melody and bass line from measure 1 reappear exchanged. That is, what was the melody in measure 1 (G A D E) appears as the bass line in measure 9. Also, what was the bass line in the measure 1 (Bb A F E) appears as the melody in measure 9. Thus, it is better to consider this composition as the rounded binary form in which whole part A returns at the end of part B. The outline is

A ||: B :||

You can click on the structural units in the outline to hear them on YouTube.

Figure: Schumann’s Norse Song from Album for the Young Op. 68 No. 41

Rondo form

A rondo form is a form usually consisting of five or seven structural units that are called the principal and episodes and in which the principal alternates with the episodes. 

The outline of this form is A B A C A or A B A C A D A. The principal is labeled A while the episodes are marked B, C and D. 

Usually, a rondo form is long enough to contain auxiliary structural units like transitions or a coda. In the chapter Form and phrases analysis, we shall examine in detail an example of the rondo form. 

Sonata form

A sonata form is an elaborate form whose outline is shown in the next figure. All auxiliary structural units are optional. 

Figure: The sonata form 

The first theme is in the home key while the second theme is usually in the home key’s dominant key (or when the home key is a minor key, the second theme may be in the home key’s relative major key). Often, the first theme has a more active character while the second theme has a more lyrical character. In the recapitulation, both themes are in the home key.

The first movement of a sonata has the sonata form (usually, the same is also true for the first movement of a symphony). Thus, a reader should make the distinction between the sonata and sonata form. The sonata is a type of instrumental compositions, while the sonata form is one of the common forms. For instance, the first movement of Mozart’s Piano sonata in C major K. 545 has the sonata form. The outline of the first movement is

First theme   Second theme  :||:  Development   First theme   Second theme :||

You can click on the structural units in the outline to hear them on YouTube. Note that the second repetition is not played in the video. During the exposition, the first theme is in the C major key (the home key) and the second theme is in the G major key (the dominant key). During the recapitulation, the first theme is in the F major key (the subdominant key) and the second theme is in the C major key (the home key). Thus, the movement is harmonically closed.