1. SECTION:  The term may refer to a major structural unit perceived as the result of the coincidence of relatively large numbers of structural phenomena; however, the term may also be used to define smaller structural units. Thus, a large section may be composed of a number of smaller ones.

2. PERIOD:  The period is a structural unit analogous to the sentence. It is typically constructed of two or more smaller units called phrases.

3. PHRASE GROUPS:  Sections in which phrases are linked by a series of cadences of an inconclusive nature.

4. OTHER STRUCTURAL UNITS:  Cadential section; closing section.

TERMS

Asymmetrical Period - each phrase differs in length.

Cadential extension - the prolongation or delay of the cadence

Contrasting Period - the two phrases are not related - a b

Double period - Two a periodic structure in which the antecedent-consequent relationship is fulfilled by pairs of phrases.

Elision--the (melodic) connection of two phrases in such a way that the cadential point of the first coincides with the beginning of the second.

Interpolation--the lengthening of the repetition of a phrase by the insertion of material not heard in the original phrase.

Link--material that appears between the end of one phrase and the beginning of the next, but belongs to neither.

Modulating--describes a period in which modulation occurs in the consequent phrase(s).

Parallel--describes a period in which the musical content of the phrases is the same.

Symmetrical--describes a period in which the phrases are the same length.

Sectional or Closed--If a section closes in the key in which it began, it is termed a closed section.

Continuous or Open--If a section does not close in the key in which it begins, it is termed an open section.

Two-reprise - Either a binary or a ternary piece is made of two repeated sections - Binary ||:A:||:B:|| - Ternary |:A:||:B A:||

American Popular Ballad Form - This is that basis of the majority of American standards and is a 32 bar AABA

1. EXPOSITORY FUNCTION:  The purpose of expository units is to "expose" musical materials that are important in the context of the complete structure's organization.  Expository units are typically characterized by clear phrase structure that is often periodic.  In tonal music, harmonic activity that serves to establish a prevailing tonality reinforces the perception of expository function.

2. TRANSITIONAL FUNCTION:  (harmonic) Serves as a connecting function between sections of relative repose in the musical context.  Transitional passages, therefore, may possess attributes that support the perception of movement, such as: unpredictable fragmentary structural units, rhythmic agitation, dynamic contrasts, and frequent changes in other structural phenomena.  In tonal music, they are characterized by harmonic activity that serves to dissolve the previously established key and to establish a new one.

3. DEVELOPMENTAL FUNCTION:  (melodic) The primary attribute of developmental passages is the presentation of motivic material heard previously in changed, or varied, form.  Such passages are often tonally unstable and thus share some of the attributes associated with transitional function.

4. TERMINATIVE FUNCTION:  The function of these passages is to bring sections of complete works to a close.  Primary attribute: tonal activity that confirms and reinforces an established key.  Continuous cadential activity and static tonality typically mark such sections.  Terminative passages may exhibit the clear phrase structure of expository units, or they may be more fragmentary in nature.  Also, such units may involve the variation of previously exposed motivic material, and thus be partially developmental in function.

A variation is simply a restatement of any musical entity that retains some elements of the original and changes others.

Procedures organized by the uninterrupted repetition of a short melodic or harmonic unit are termed: continuous variations.

Procedures whose themes and variations are closed, complete structural units are termed:  sectional variations.

Continuous Variations

Continuous variation procedures tend to fall into two types:

• those based upon a single melodic unit (usually in the bass);
• those based upon a harmonic progression.

The first type is appropriately called:  ground bass or basso continuo.

Two terms have been applied to both types:  chaconne and passacaglia. Chaconne, however, is more commonly associated with the latter.

*Recall from Counterpoint class:  chaconne refers to harmonic succession; passacaglia refers to a repeated melodic line.  They are at times difficult to distinguish.  (Memory tip: Relate the "ch" in chaconne to "ch"ord to remember that chaconne refers to a repeated chord/harmonic progression.)

General features of continuous variations:

1. The theme (bass melody or harmonic progression) is usually repeated throughout in the same key.

2. The process of variation is achieved by the changing character of elements other than the theme.

3. The theme may be melodically or harmonically altered or ornamented.

4. The theme may be subject to change in register.

In contrast to continuous variations, in which the theme is a short bass melody or a harmonic progression, the theme of sectional variations is a complete musical entity with melodic, harmonic, and rhythmic identity.

In addition, the theme is typically of larger dimensions than a single phrase--periodic or binary structures are commonly encountered--and reaches a definite conclusion before the first variation begins.  In the same manner, each variation is perceived as a self-contained musical unit.

General features of theme and variations compositions:

1. The theme (particularly since the Classical period) is generally a binary structure.

2. There are variation techniques that are commonly exploited, such as:  melodic ornamentation, melodic figuration, melodic simplification (representation of the theme's melody in skeletal form); changes in mode, meter, tempo; contrapuntal development; the use of attributes associated with other pieces, such as dance movements.