STRUCTURE OF COMPOSITION

The structure of compositions is hierarchical and it consists of a few levels. At each level, structural units are divided into smaller structural units. 

At the top level, there is a whole composition that is divided into one or more movements. A single-movement composition consists of only one movement while a multi-movement composition consists of two or more movements. The next figure shows a multi-movement composition that consists of three movements. 

Figure: A multi-movement composition that consists of three movements

A form is an overall plan of a movement. A movement can be a whole single-movement composition or one movement of a multi-movement composition. A form is similar to a blueprint of a building. It shows the structure and helps in seeing the big picture, especially when the big picture is complex. 

The theory of forms examines middle and bottom levels of the structure of compositions. At middle levels, movements are divided into smaller structural units. These structural units can be further subdivided into smaller structural units until the bottom level is reached. At the bottom level, phrases and periods appear. Phrases and periods will be explained in the following chapters.

Common forms are templates for form and describe middle levels of the structure of compositions. They will be explained in the chapters that follow those related to phrases and periods. It is hard to say anything in general about middle levels because almost everything depends on the chosen common form. Even the terminology used differs somewhat from one common form to the other. However, a few general terms will be defined in this chapter.

The structural units on the middle level can be core or auxiliary. Core structural units contain core material while auxiliary structural units contain auxiliary material. While core structural units must appear, auxiliary structural units usually appear only in longer movements. Possible auxiliary sections are: an introduction, transition, coda and codetta. The introduction can appear only at the beginning of a movement. A transition can appear between any two adjacent core structural units. The coda can appear only at the end of a movement. “Coda” in English means “tail”. A codetta can appear only at the end of a core structural unit which is further divided into smaller structural units. “Codetta” in English means “small tail”. The next figure illustrates core and auxiliary structural units. 

Figure: A movement that is divided into core and auxiliary structural units (which are marked in blue)

Core structural units are labeled by material that is contained in them. In this case, uppercase letters are used for labeling core structural units. For instance, we can say that the outline of the form of a movement is A B A. This means that the movement contains three core structural units. The first and third are the same or similar and thus are annotated with the same letter A. The second one is different from them and thus is annotated with the different letter B. If the first and third are not the same but only similar, we can use numbers to emphasize this. In this case, instead of writing A B A, we can write A1 B A2. Numbers are used to distinguish different variants.