Theory III Form Glossary

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Harmonic elements of Form

Melodic elements of Form

Forms and Phrase Structure

Rhythmic, descriptive and textural elements of form


Harmonic elements of Form

authentic-cadence: a cadence harmonic formula consisting of a stop on tonic chord
preceded by a dominant-function chord; e.g. V I, or vii6 I.

cadence: a pause or stopping point. Often cadences are associated with harmonic or melodic formulae; e.g. an authentic cadence is a stop with the chords V to I. A "Landini cadence" is a melodic formula that proceeds as 8-7-7-6-8 (scale degrees).

deceptive-cadence: a cadence formula that moves from dominant to submediant.

half-cadence: a cadence on the dominant.

harmonic-rhythm: the rate of chord change.

harmonic-sequence: a repeating pattern of root-movements manifested as a chord
progression.

modulation: 1. a change of key-- a combination of a tonic and a mode. 2. a smooth, gradual change from one state to another, e.g.tempo, key, meter, timbre, etc.

pivot-chord: (syn. common-chord) a chord that functions in two different keys and is used to modulate from one key to another.

plagal-cadence: the cadence formula IV I.


Melodic elements of Form

motive: a brief melodic or rhythmic idea used to organize a composition.

ostinato: a series of notes that is repeated over and over again in the bass, usually a part of a theme-and-variations.

theme: a compositional idea that recurs, normally melodic, that is of some length, i.e., is a
complete musical statement in itself.

Forms and Phrase Structure

antecedent phrase: the first phrase of a period, ending with a cadence, usually weaker than the cadence that concludes the consequent phrase of the period.

cadential extension: the prolongation or delay of the cadence by the adition of material to the closing phrase.

closing section (coda): a musical section that brings a work or larger section to a close. Harmonic and melodic activity usually lead up to and reinforce -- or simply repeat -- the final cadence.

consequent phrase: the second phrase of a period, ending with a cadence, usually stronger than the cadence that concludes the antecedent phrase that preceded it.

developmental: a musical section that amplifies or devlops material already introduced. Developmental sections are less stable harmonically, melodically and rhythmically that expository sections, and usually more complex than closing sections.

double period: a period in which the antecedent-consequent relationship is fulfilled by pairs of phrases.

elision: the connection of two phrases so that the cadence of one overlaps with the beginning of another.

expository/thematic function: the musical section that sets out the primary thematic and harmonic materials of a work. The melodic, harmonic, and rhythmic elements of the exposition are usually clearer and more regular than that of following developmental sections.

forms (musical): existing structural frameworks that are used to compose music; e.g. binary (AB), ternary (ABA), sonata, rondo, fugue, etc.

fugue: a contrapuntal form that is built from a single subject and has an exposition where all voices state the subject in turn, alternating tonic and dominant entrances. The fugue continues with various contrapuntal artifices and usually has several sections that are a combination of subject-sections, episodes, counterexpositions, stretti, etc.

genre: classification of music by some combination of function, medium, form, or idiom;
examples are: opera (voices, orchestra, dramatic action, staging), etude (an exercise composed for developing skills on an instrument), lullaby (song used to put one to sleep), dirge (a funeral music).

passacaglia: (syn. chaconne). a slow theme-and-variations in triple meter with the theme
recurring in the bass.

period: a pair of balanced phrases, antecedent and consequent, that occur consecutively, are
united by motivic similarities, and make up a complete statement. Periods are often characterized as parallel (similar phrases with different endings), contrasting (different in melodic/harmonic design), symmetrical (both phrases are the same length) or asymmetrical.

phrase: a musical statement, with a beginning, end, and a clear shape, usually melodic.

phrase group: a musical statement, with a beginning, end, and a clear shape, usually melodic.

section: a structural unit produced by some kind of structural division (cadence, change in tonality or texture, etc.)

transitional function: material that connects expository, developmental, or closing sections of a work.

Rhythmic, descriptive and textural elements of form

counterpoint: (adj: contrapuntal) two or more simultaneous, independent lines or voices.

fragmentation: the use of a part of a melodic line instead of its entirety. It is a common
technique of thematic variation.

hemiola: a metric pattern of triple in a normally duple meter or, vice versa, a pattern of duple in a normally triple meter. Hemiola need not be confined to duple and triple meters, however. It is used applied to any type of metrical anomaly.

idiom: aspect of composition that is especially adapted to, or explores, an instrument's
capabilities.

picardy-third: the use of a major third in a cadence on the tonic in a minor key.