Topic 1: Subphrases, Periods, Sentences, and Motives
Period—two or more phrases in succession that form a single musical unit because the last phrase’s cadence is more conclusive than the preceding cadence(s). Note: it can also mean a single phrase ending in a PAC. The issue is closure; a unit that ends conclusively is a period.
A period usually consists of two phrases, an antecedent and a consequent. If the antecedent is a question (?), the consequent is the answer (.).
Periods We Are Most Likely to Encounter
A period has two main aspects: the degree of similarity between its melodies and its harmonic plan, with a focus on the cadences. Similar melodic material may help phrases sound like a unit, but this is not necessary in order for phrases to form a period. The main thing is that the period reserves its most conclusive cadence for the end.
- Melodic types
Parallel: The phrases’ melodies begin similarly or in exactly the same way.
Contrasting: The phrases’ melodies differ significantly.
- Harmonic plans
Interrupted: The antecedent ends with a HC or an AC in V; the consequent begins back on the tonic harmony and ends with an AC. Continuous: The antecedent ends with a HC, or with a cadence in a new key. The consequent does not begin with tonic; and it ends with an AC.
Sectional: The antecedent ends with an IAC; the consequent ends with a PAC.
Progressive: The consequent modulates and ends with an AC in a new key.
Three- and Four-Phrase Periods
Some periods have more than two phrases.
Asymmetrical periods—three-phrase periods
Double periods—four-phrase periods
Double periods often divide into two pairs of phrases on the basis of melodic repetition: a1 b1; a1 b2. That creates a parallel double period. The first two phrases form a large-scale antecedent, and the second two form a large-scale consequent. Here is a typical harmonic plan: IAC HC; IAC PAC. This an interrupted or a continuous period, depending on whether the second half (phrase 3) begins back on tonic or begins with another chord.
Listening to Periods
The distinctions used for characterizing periods (and larger sections of music, as well) depend on two aural skills:
- Hear whether melodic material returns, perhaps in varied form.
- Identify the cadences.
To distinguish between interrupted and continuous periods, one must also distinguish between phrases that begin on the tonic chord or on some other harmony.
Periods and Sentences, with application to “Christ the Lord is Risen Today”
Analysis of Haydn, String Quartet in E-flat major, Op. 76, No. 6
Analysis of Mozart, Piano Sonata, K. 576
Topic 2: Diatonic Sequences
Sequence – the statement of a pattern two or more times in a row, with each new statement of the pattern being a consistent, generic interval (2nd, 3rd, etc.) higher or lower than the previous one.
A complete label has three parts. To begin, identify the repeated pattern–the pattern being sequenced. I like to box or bracket each occurrence of the pattern in the score. Then
- provide the interval of restatement—the interval between one statement of the pattern and the next,
- provide the root motion from chord to chord in parentheses, and
- note the types of chords using figures.
Most sequences have patterns comprised of just two chords. That means that there are two figures to record for a sequence, although one of them is often blank, thus representing a root-position triad.
Instead of complete labels, we may also use a shorthand involving the conventional labels shown in the table below. A shorthand label consists of a conventional label followed by the figures (eg. ↓5, 6).
* Chordal 7ths can be added to descending fifths sequences:
↓5 (7th chords), ↓5 (alternating 7ths), ↓5 (alternating 65’s), and ↓5 (65 and 42’s) are all common.