IV. Diatonic Harmony, Tonicization, and Modulation
Predominant Seventh Chords
John Peterson
Key Takeaways
- This chapter discusses the predominant seventh chords ii7, IV7, vi7, and iii7.
- ii7 and its inversions are the most common predominant seventh chord, and shows which inversions of ii7 are more common than others.
- When writing with predominant seventh chords, two general principles apply with respect to the treatment of the chordal seventh:
- Approach the chordal seventh by step or common tone.
- Resolve the chordal seventh down by step.
Earlier, we saw how adding a chordal seventh to the dominant strengthened its drive toward the tonic. In this chapter, we see that something similar can be accomplished by adding a chordal seventh to predominant chords: it can intensify their motion to the dominant ( ). Adding a seventh to ii chords is common; it also occurs with the other predominant chords (particularly IV and vi), but less frequently. All predominant seventh chords share two general guidelines for the treatment of a chordal seventh:
- The chordal seventh is usually approached by step or common tone.
- The chordal seventh resolves down by step.
. A predominant seventh chord in Josephine Lang, “Dort hoch auf jenem Berge”
Adding a chordal seventh to ii
lists the various inversions of ii7 from more common to less common. We’ll discuss each in turn.
| Degree of commonality | Inversion of ii7 |
|---|---|
| Most common | [latex]\mathrm{ii^6_5}[/latex] |
| Somewhat common | [latex]\mathrm{ii^7}[/latex] |
| Less common | [latex]\mathrm{ii^4_2}[/latex] |
| Least common | [latex]\mathrm{ii^4_3}[/latex] |
ii[latex]^6_5[/latex]
[latex]\mathrm{ii^6_5}[/latex] often substitutes for [latex]\mathrm{ii^6}[/latex], meaning that it commonly shows up near the end of a phrase ( typical part writing procedures and treatment of the chordal seventh, there aren’t any new voice leading concerns when writing with [latex]\mathrm{ii^6_5}[/latex] ( ).
). Other than the
ii7
ii7 is typically found near the end of a phrase (typical writing procedures and treatment of the chordal seventh, there are two main issues to be aware of when writing with ii7:
). In addition to following- The chord is often preceded by tonic, and it’s best to use I6 rather than I to avoid potential parallels,
- When ii7 resolves to V7, either ii7 or V7 will need to be incomplete to avoid causing a voice-leading problem ( ).
ii[latex]^4_2[/latex]
[latex]\mathrm{ii^4_2}[/latex] typically expands tonic at the beginning of a phrase in the progression [latex]\mathrm{I-ii^4_2-V^6_5-I}[/latex] (typical writing procedure and treatment of the chordal seventh.
). This progression is easy to write if you follow the
ii[latex]^4_3[/latex]
[latex]\mathrm{ii^4_3}[/latex] 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 typical writing procedure and treatment of the chordal seventh, there isn’t anything new to learn about voice leading.
Other predominant sevenths
The remaining predominant sevenths, IV7, vi7, and iii7 are not nearly as common as ii7 and its inversions. Among them, IV7 and vi7 are more common than iii7, which makes sense given that [latex]\mathrm{iii}[/latex] as a triad isn’t very common in the first place. Both IV7 and vi7 tend to show up as root-position chords when they’re used, and vi7 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, V7 to vi7 is not common). typical writing procedures and treatment of chordal sevenths.
shows sample voice leading involving these chords. It follows
Refers to the seventh above the root of a chord. For example, V⁷ in the key of C is spelled G-B-D-F; F is the chordal seventh.
1. Write the entire bass
2. Write the entire soprano to make a smooth melody that interacts well with the bass. Choose active notes for the soprano above dominant-function chords, and remember you do not always need to write left to right.
3. Write the inner voices by asking, "What notes do I already have? What notes do I still need? Considering spacing and resolution, what note placement would give me the smoothest motion?"
In strict four-voice writing:
1) Approach the chordal seventh by step or common tone
2) Resolve the chordal seventh down by step
Reminder: the chordal seventh is different from the leading tone.