DIATONIC PROCEDURES III
|Chapter 18. Tonic Substitutions|
19.1 LEADING TONE 7
The leading tone triad, like the dominant, can easily become a tetrad by adding ^6. As with the dominant 7, this dissonance intensifies the instability of the chord, and that 7th must resolve down by step (to ^5). The leading tone 7 can be found in any position.
In major keys, the 7th of the leading tone 7 is the ^6 (La) which forms a dm7.
In minor keys, the 7th of the leading tone 7 is the lowered ^6 (Le) which forms a dd7.
19.2 POSITIONS OF LEADING TONE SONORITIES
Leading tone sonorities are interchangeable with the dominant areas discussed in Chapter 14, and are used in exactly the same ways, depending on the scale degree in the bass line.
|^7||do not use|
|^2||P or N|
|^7||P, N, or IN|
|^2||P or N|
|^4||N or IN|
Leading tone and dominant sonorities are all forms of "dominance", and provide an instability that must resolve ultimately to some form of tonic. Absent from the chart above is the 3rd inversion of leading tone 7, which places ^6 in the bass. This inversion does not form a standard function (such as passing or neighboring) and needs to be explained in its specific context.
19.3 MEDIANT IN MAJOR KEYS
When the mediant occurs in 1st inversion in major keys, ^5 is in the bass. Due to this similarity with dominant, it can serve as a weak substitute for dominant. It is so weak that it should only be used in subordinate progressions, never in cadences.
19.4 MEDIANT AND SUBMEDIANT IN MINOR KEYS
The mediant triad is augmented when the leading tone is utilized, and makes an excellent substitute for dominant. It works equally well in root position and 1st inversion.
The submediant goes through an interesting change when the raised ^6 is used. In minor keys, the major submediant (with the lowered ^6) is an excellent substitute for tonic (just as in major keys). But when ^6 is raised, the submediant becomes diminished, and makes a poor tonic substitute. This unstable triad (or tetrad if the 7th is added) works better as a passing or neighboring chord, to prolong dominance.
The concept of "dominance" (which includes all forms of dominant and leading tone sonorities) is inviolate. The necessity of dominance to resolve to tonic cannot be questioned, due primarily to the power of ^7 (leading tone). There are, however, two harmonic areas that resemble dominance (and even use the same Roman numerals), but function in a completely opposite manner: MINOR DOMINANT and SUBTONIC.
19.6 MINOR DOMINANT
Dominant in a minor key is a minor triad when lowered ^7 (Te) is used. Without the power of the leading tone, this dominant no longer serves the same function. This triad is MINOR DOMINANT (the only time a quality is required to define a harmonic area) in order to distinguish it from the true dominant function, and under no circumstances should it be used in the capacity of dominant. Its purpose is to move away from tonic.
The subtonic triad is like the minor dominant: the absence of leading tone takes away the power to move towards tonic. It has nothing in common with the leading tone triad and is used to move away from tonic.
19.8 UPDATED DEFINITION OF SONORITY
Information presented in this chapter (and earlier) requires an updated definition of
"sonority" as given in Chapter 4:
The essential sonority (chord) is consonant and is a group of three notes (a triad) arranged in thirds (tertian). Dissonance is used, which could be a group of four notes arranged in thirds (a tertian tetrad) or non-chordal embellishments (passing and neighboring tones, suspensions, and pedals, among others). All dissonances are required to resolve.
At this point, all diatonic vocabulary has been covered. The next chapter will begin to present chromatic materials. Dr. Rush presents a succinct approach to harmonic motion:
Learn more about harmonic progression
Tonic, dominant (7), supertonic (7), subdominant in several positions, leading tone in first inversion, all the 6/4 types, tonic substitutes (submediant and mediant), and dominant substitutes (leading tone 7 and mediant) [new items in red]
This will be the last chapter with the harmonic charts. Areas with an * indicate possible sonorities that will be dealt with as found in future analysis exercises.
I. Provide a Roman numeral and structural analysis, and circle and label all non-chord tones, for the following piece:
II. Describe the phrase design and provide a Roman numeral and structural analysis for the following pieces in Music for Analysis:
Add soprano, alto, and tenor lines to this figured bass, and include, using the indicated rhythm, at least 2 passing tones, 2 neighbor tones, and 2 suspensions (never more than one in any given beat) in the upper three voices. Circle and label the non-chord tones and provide a Roman numeral and structural analysis:
To prepare this writing assignment properly, use the notation guidelines appendix, located at Basic Principles of Music Notation, Semester II.
Link to chapters in this unit:
|Chapter 18. Tonic Substitutions|
Link to previous unit: DIATONIC PROCEDURES II: Expanding the Phrase
Link to next unit: CHROMATIC PROCEDURES I: Moving from the Global Key
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