MUS 112 Study Guide P (Chapter 16)
The v and VII Triads; The Phrygian Cadence
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The v and VII triads, along with the seldom-used vio
and III+, the last of the diatonic triads, occur only in
minor. The Phrygian cadence also finds more use in minor than
The Minor Dominant Triad (v): Since you
are familiar with the behavior of the 6th and 7th
scale degrees in (melodic) minor, you now may be able to imagine why
the minor dominant chord may appear, even though it is rare.
It would appear in a situation where the descending melodic line
(using the lowered 7th and 6th scale degrees)
happens to place the lowered 7th in conjunction with a
dominant chord harmonization. For example, in C minor, the
descending scale would be: C Bb Ab G, etc. If
the Bb were to be harmonized using the dominant chord, that
chord would be G minor.
- The Subtonic Triad (VII): in minor keys, built
on the subtonic (b7); it does not function as does viio,
built on the leading tone. Usually the root of VII moves down
a perfect fifth to III. Notice that this transposed "V-I"
relationship causes the second chord, III, to sound like a
tonic. (When a chord progression other than V-I or V-i
suggests that the second triad could be tonic, even if only briefly,
the first triad is called a secondary dominant. This
process is called tonicization. We will study secondary
dominants in greater detail later.)
So, VII-III and III-VI present dual auditory impressions:
(1) a simple diatonic progression in a key, and, (2) a tonicizing of
the second triad.
The subtonic triad (VII) appears most often in a harmonic
sequence, or in a change of key, called modulation ... again,
to be studied later.
- The Progression iv-VII: In a minor key, the root of iv is a
perfect fifth above the root of VII. Thus, iv is useful both
in a iv-VII progression and in the common iv-V and IV-viio
progressions. Most commonly, iv-VII is used in the harmonic
sequence known as the circle progression.
- The Triads vio and III+: The use of vio
is very limited. It harmonizes the #6 scale degree in
minor. As a diminished triad, it usually appears in first
inversion to eliminate the tritone interval. The III+ is an
augmented triad, of course. It appears due to the raised
leading tone (#7, which is the fifth of the triad) of the minor key.
- The Medieval Modes (Appendix D): The modes were used
extensively from medieval times to the seventeenth century, and have
seen a resurgence in popularity during the Impressionist era and 20th
Century. These are like the major and minor scales in that all
consist of seven scale steps. But each mode begins on a
different letter name and uses only the "white notes" of
the keyboard. Therefore, the location of half and whole steps
differ in each mode, creating a different "flavor" for
The first scale step in any mode is known as its final,
rather than "tonic." (The concept of tonality had not
yet been developed when modes first came into use.)
When the range of the melody is generally between the final and its
octave, the mode is said to be authentic.
When the range of the melody is generally between the fifth of the
scale and its octave, the mode is said to be plagal. The
prefix "hypo-" becomes part of the name of the plagal modes,
e.g., hypodorian, hypophrygian, etc.
Our modern "major" scale corresponds to the Ionian
mode, and our "natural minor" scale corresponds to the aeolian
A mode on B, called Locrian, is theoretical. Because it has a
tritone from its tonic to its dominant (B-F), it was not considered
Following is a list of the medieval modes:
Dorian: like natural minor but with a
raised 6th scale step.
Phrygian: like natural minor but with a lowered 2nd
Lydian: like major but with a raised 4th scale
Mixolydian: like major but with a lowered 7th
Aeolian: same as natural minor.
Ionian: same as major.
As with the major and minor scales, the modes may
begin on any tone as long as the arrangements of half and whole
steps remain the same. Since the final of each transposed mode
lies in the same relationship to the tonic of the major scale with
the same key signature, the identity of a transposed mode can be
Dorian: The final is always the second degree of a
major scale. E.g., a mode which shares the key signature with F
major but whose final is a G (2nd scale degree in F) would
be a dorian mode transposed to G, referred to as G Dorian.
Phrygian: The final is always the third degree of
a major scale. E.g., a mode which shares the key signature with
D major but whose final is an F# (3rd scale degree in D)
would be a phrygian mode transposed to F#, referred to as F# Phrygian.
Lydian: The final is always the fourth degree of a
major scale. E.g., a mode which shares the key signature with A
major but whose final is a D (4th scale degree in A) would
be a lydian mode transposed to D, referred to as D Lydian.
Mixolydian: The final is always the fifth degree
of a major scale. E.g., a mode which shares the key signature
with Bb major but whose final is an F (5th scale
degree in Bb) would be a mixolydian mode transposed to F,
referred to as F Mixolydian.
Aeolian: The final is always the sixth degree of a
major scale. E.g., a mode which shares the key signature with Ab
major but whose final is an F (6th scale degree in Ab)
would be an aeolian mode transposed to F, referred to as F Aeolian.
Ionian: The final is always the first degree of a
major scale. E.g., a mode which shares the key signature with G
major would have the same final (1st scale degree in G) as
the tonic, therefore, it would be an ionian mode transposed to G, or G
Ionian (same as G major).
- Determining a Transposed Mode: This is the above procedure
in reverse. Examples:
The final is an A and the key signature has one sharp: The
major key would be G. Since A is the second scale degree
in G major, the transposed mode would be ... dorian.
The final is a G and the key signature has three flats. The
major key would be Eb. Since G is the third scale
degree in Eb major, the transposed mode would be ... phrygian.
The final is a G and the key signature has two sharps. The
major key would be D. Since G is the fourth scale degree
in D major, the transposed mode would be ... lydian.
The final is F# and the key signature has five sharps. The
major key would be B. Since F# is the fifth scale degree
in B major, the transposed mode would be ... mixolydian.
The final is Eb and the key signature has six flats.
The major key would be Gb. Since Eb is the sixth
scale degree in Gb major, the transposed mode would be ...
The final is E and the key signature has four sharps. The
major key would be E. Since E is the first scale degree
in E major, the transposed mode would be ... ionian.
Note: On occasion, composers will use "incomplete"
key signatures. That is, the key signature may have only two
sharps, but the accidental G# will appear throughout the
composition. In such cases, one should consider that the
equivalent major key signature has "three" sharps rather
than two in determining the transposed mode. (Pretty sneaky,
- Half Cadences; the Phrygian Cadence: Any diatonic
triad except viio and VII can precede the V triad to
create a half cadence at an appropriate cadential point.
Common are ii-V and IV-V, in both major and minor. One of
these, iv6-V (in minor), carries a special designation,
the Phrygian cadence. In this cadence, the soprano
descends by whole step while the bass descends by half step–a
characteristic of the phrygian mode (b2-1). Even if the
voices are reversed and the half step occurs in the soprano, the
cadence would still be considered phrygian.
The phrygian cadence also exists, though rare, in a major key as ii6-III.
The III triad in a major key is usually considered a secondary
dominant chord (to be studied later). But as a member of the
phrygian cadence it usually returns directly to tonic.
- Writing the v and VII Triads in a Minor Key: No new
part-writing procedures are required for either of these
triads. Each triad contains a lowered 7th scale
In the dominant minor (v), this tone must descend.
In the VII triad, the lowered 7th scale degree assumes
the role of the root of a secondary dominant chord; therefore, its
properties are the same as those of the root of the dominant triad.
- Writing the Phrygian Cadence: In the phrygian cadence, the
iv6 triad can be written with any doubling.
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