IV. Diatonic Harmony, Tonicization, and Modulation

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 Example 2 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 :
    • 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 to predominant chords: it can intensify their motion to the dominant (Example 1). 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:

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

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

Adding a chordal seventh to ii

Example 2 lists the various inversions of ii7 from more common to less common. We’ll discuss each in turn.

[table id=46 /]

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

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 (Example 1). Other than the and, there aren’t any new voice leading concerns when writing with [latex]\mathrm{ii^6_5}[/latex] (Example 3).

Example 3. Writing with ii[latex]\mathit{^6_5}[/latex].

ii7

ii7 is typically found near the end of a phrase (Example 1). In addition to following and , there are two main issues to be aware of when writing with ii7:

  1. The chord is often preceded by tonic, and it’s best to use I6 rather than I to avoid potential parallels,
  2. When ii7 resolves to V7, either ii7 or V7 will need to be incomplete to avoid causing a voice-leading problem (Example 4).

Example 4. Writing with ii7.

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] (Example 5). This progression is easy to write if you follow the and .

Example 5. Writing with ii[latex]\mathit{^4_2}[/latex].

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 (Example 6). Other than following the and seventh, there isn’t anything new to learn about voice leading.

Example 6. Writing with ii[latex]\mathit{^4_3}[/latex].

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). Example 7 shows sample voice leading involving these chords. It follows and .

Example 7. Writing with IV7 and vi7.

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

License

Icon for the Creative Commons Attribution-ShareAlike 4.0 International License

OPEN MUSIC THEORY by John Peterson is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License, except where otherwise noted.

Share This Book