In Unit 16, we looked at the most common methods used in music to modulate from one key center to another.
In the majority of those examples, the modulation was to a closely related key, allowing the modulatory methods to rely on the number of pitches and chords that were common to both keys. When music modulates to a distant key–without passing through multiple intermediary keys–the methods for modulation require more complicated techniques.
The following examples demonstrate advanced modulatory methods in simplistic renditions of a four-part chorale. They are written in such a way to highlight a particular modulatory technique and are grouped in pairs to give you multiple examples of the same idea. Listen to each pair of examples, and identify the commonalities within each pair. For each example:
What qualities do this first pair of examples have in common? How would you describe the modulation? Is this similar to any of the original modulatory techniques from Unit 16. Make sure that you can answer all of the questions in the above instructions before moving on to the next group.
The Group A examples modulate by pivoting on a borrowed chord (mode mixture). The first phrase establishes the original key but uses a borrowed chord to provide a colorful alteration. In the second phrase, the borrowed chord is then turned into a pivot chord. For Modulation 1, the borrowed bVI chord becomes a V in the key of D-flat major. In Modulation 2, the borrowed iv chord becomes the ii chord in the key of E-flat major.
As with all pivot chord modulations, these will typically occur in the middle of the phrase because a pivot chord modulation relies on having a functional chord progression on both sides of the pivot. The smoother the chord progression on both sides, the smoother the modulation will sound.
The excerpts in Group B demonstrate the extreme flexibility of a fully diminshed seventh chord. Because this chord is symmetrical, it can be enharmonically respelled to form four different chords. Look at the chart below to see how one diminished seventh chord can be respelled to be four different chords.
| Spelling 1 | Spelling 2 | Spelling 3 | Spelling 4 |
|---|---|---|---|
| A-flat | G-sharp | G-sharp | A-flat |
| F | F | E-sharp | F |
| D | D | D | D |
| B | B | B | C-flat |
| viio7/C | viio6/5/A | viio4/3/F-sharp | viio4/2/E-flat |
The way in which a fully diminished chord is spelled denotes the key in which it will naturally occur. These keys are shown in the bottom row of the chart along with the inversion figure for this particular spelling.
In Modulation 3 above, the first phrase uses a viio4/2 chord as a passing chord to move into a cadential 6/4 progression. In the second phrase, this viio4/2 chord is respelled to become a viio7 thus creating a functional pivot into the new key of A major.
Modulation 4 begins identically to Modulation 3, but when we reach the viio4/2 in the second phrase, it is respelled as a viio4/3 which acts as the pivot into the new key of F-sharp minor.
Note that there are even further possibilities for modulations if the fully diminished chord is used a secondary leading-tone chord (viio7/x) in one or both of the keys.
Both of the examples in Group C use the fact that a Ger+6 chord is enharmonically equivalent to a dominant seven chord, and this can be used to create V7 in a distant key. The first phrase of Modulation 5 is a standard diatonic progression, but in the second phrase, the V7 chord is enharmonically respelled to become the Ger+6 in the key of B major. As is typical of a Ger+6, it moves through a cadential 6/4 chord before finishing on a perfect authentic cadence.
Modulation 6 uses a Ger+6 as the predominant in the first phrase, but in the second phrase, the Ger+6 is respelled to become an A-flat dominant seventh chord; allowing it to become the V7 chord in the key of D-flat major.
There is one other symmetrical chord which can be enharmonically respelled that we will not cover in this section. The Fr+6 chord can be respelled to become a different Fr+6 chord because it contains two whole steps separated by a M3 on either side. For example, the Fr+6 in C major consists of pitches the A-flat, C, D, and F-sharp. If the F-sharp is respelled as a G-flat, the chord can be re-arranged to become the Fr+6 in the key of G-flat (D, G-flat, A-flat, and C). This is not a common modulation, but it is worth remembering in the rare chance that you encounter this in a piece of music.
As with all modulation techniques, these modulatory tricks rely on setting the listener’s expectations before presenting them with a dramatic modulation. Because chords such as the Ger+6 are less common than standard diatonic progressions, it is most common to see these sorts of modulations in a second phrase after having established the uncommon chord or progression functioning “normally” in the first phrase. This creates the sense of expectation for the second phrase before the surprise of the modulation.