IV. Diatonic Harmony, Tonicization, and Modulation

# Predominant Seventh Chords

John Peterson

Key Takeaways

• This chapter discusses the predominant seventh chords $\mathrm{ii^7}$, $\mathrm{IV^7}$, $\mathrm{vi^7}$, and $\mathrm{iii^7}$.
• $\mathrm{ii^7}$ and its inversions are the most common predominant seventh chord, and Example 2 shows which inversions of $\mathrm{ii^7}$ are more common than others.
• When writing with predominant seventh chords, two general principles apply with respect to the treatment of the chordal 7th:
• Approach the chordal seventh by step or common tone
• Resolve the chordal seventh down by step

Earlier we saw how adding a chordal 7th to the dominant strengthened its drive toward the tonic. In this chapter we see that something similar can be accomplished by adding a to predominant chords: it can intensify their motion to the dominant (Example 1). Adding a seventh to ii chords is common. While composers do sometimes add a 7th to the other predominant chords (particularly IV and vi), it’s not as common as with ii. All predominant 7th chords share two general guidelines for the treatment of a chordal 7th:

1. The chordal 7th is usually approached by step or common tone
2. The chordal 7th resolves down by step

Example 1. A predominant seventh chord in Josephine Lang, “Dort hoch auf jenem Berge”

# Adding a chordal 7th to ii

Example 2 lists the various inversions of $\mathrm{ii^7}$ from more common to less common. We’ll discuss each in turn.

Degree of commonality Inversion of ii7
More common ii$\begin{smallmatrix}6\\5\end{smallmatrix}$
ii7
ii$\begin{smallmatrix}4\\2\end{smallmatrix}$
Less common ii$\begin{smallmatrix}4\\3\end{smallmatrix}$

Example 2. Inversions of ii7 sorted by relative degree of commonality.

## $\mathrm{ii^6_5}$

$\mathrm{ii^6_5}$ often substitutes for ii6, meaning that it commonly shows up at the end of a phrase (Example 1). Other than the and, there aren’t any new voice leading concerns when writing with $\mathrm{ii^6_5}$ (Example 3).

Example 3. Writing with $\mathit{ii^6_5}$.

## $\mathrm{ii^7}$

$\mathrm{ii^7}$ is typically found at the end of a phrase (Example 1). In addition to following and , there are two main issues to be aware of when writing with $\mathrm{ii^7}$:

1. The chord is often preceded by tonic, and it’s best to use $\mathrm{I^6}$ rather than I to avoid potential parallels
2. When $\mathrm{ii^7}$ resolves to $\mathrm{V^7}$, either $\mathrm{ii^7}$ or $\mathrm{V^7}$ will need to be incomplete to avoid causing a voice leading problem (Example 4).

Example 4. Writing with ii7.

## $\mathrm{ii^4_2}$

$\mathrm{ii^4_2}$ typically expands tonic at the beginning of a phrase in the progression $\mathrm{I-ii^4_2-V^6_5-I}$ (Example 5). This progression is easy to write if you follow the and .

Example 5. Writing with $\mathit{ii^4_2}$.

## $\mathrm{ii^4_3}$

$\mathrm{ii^4_3}$ is relatively uncommon. When it does show up, it’s usually in place of a strong predominant at a phrase ending. Other than following the and , there’s not anything new to learn about voice leading (Example 6).

Example 6. Writing with $/mathit{ii^4_3}$.

# Other predominant sevenths

The remaining predominant sevenths, $\mathrm{IV^7}$, $\mathrm{vi^7}$, and $\mathrm{iii^7}$ are not nearly as common as $\mathrm{ii^7}$ and its inversions. Of them, $\mathrm{IV^7}$ and $\mathrm{vi^7}$ are more common than $\mathrm{iii^7}$, which makes sense given that $/mathrm{iii}$ as a triad isn’t very common in the first place. Both $\mathrm{IV^7}$ and $\mathrm{vi^7}$ tend to show up as root position chords when they’re used, and $\mathrm{vi^7}$ only shows up as a harmony connecting the tonic area to the strong predominant area, and not as part of a deceptive motion (in other words, $\mathrm{V^7}$ to $\mathrm{vi^7}$ is not common). Example 7 shows sample voice leading involving these chords. It follows and .

Example 7. Writing with $\mathit{IV^7}$ and $\mathit{vi^7}$.

Assignments
1. Pre-dominant Seventh Chords (.pdf, .docx). Asks students to realize figured bass and analyze. 