Lesson 7a - Using Voice-leading to Create a Harmonic Progression

We now have the analytical foundation and tools to begin studying harmonic function–how and why a chord works with other chords to build tonality. In this lesson, we will derive the basic aspects of function by combining two major concepts from previous units:

1. As shown in the two-part examples in Unit 6b, the progression from V⁷ to I creates a strong and natural sense of resolution. There are many reasons we hear this progression as a strong cadence, but perhaps the strongest reason is the voice-leading between the V⁷ and I chords–meaning the way in which individual pitches naturally pull toward each other.
2. When written as a scale, diatonic collections are simply a sequence of five whole steps and two half-steps–the major scale, for example, is W-W-H-W-W-W-H–but as we determined in Unit 2c, you can find all seven pitches in the diatonic collection by altering a a single half-step in a circle-of-fifths. This alteration changes one of the P5 intervals to a d5, and it is these two pitches within the diatonic collection, ti and fa, that establish the voice leading that pulls V⁷ to I and therefore around which tonal harmony is constructed.

As a side note, the significance of cultural conditioning cannot be overlooked. A person who grows up listening to any style of music will be conditioned to hear the tendencies used in that music as a natural progression, and this holds true for those raised around music descended from the diatonic tradition. This does not change the importance of voice-leading in forming these progressions, but it is worth remembering the difference between laws, rules, and strategies discussed in the first reading from Unit 6.

The examples below demonstrate how these half-steps create this the foundation of diatonic harmony. If you understand the voice-leading principles that pull the V chord into the I chord, you can then extend these rules to create the basic progression from which all diatonic harmony evolves.

Goals for this topic

The next five examples are meant to expose the logic behind the voice-leading of standard diatonic harmonies. To use these, study each example before moving on to the next and form a hypothesis regarding the voice leading (which chord tones resolve or pull to other chord tones). Once you have developed a theory as to how and why the progression works, move to the next example to see if your hypothesis can be applied. If it cannot, alter your hypothesis to account for both examples. Continue this way until you have found voice-leading rules that apply to all of the examples.

This example has two idealized progressions of a V chord resolving to a I chord: one as triads and the other with a seventh chord.

• Study how each voice resolves.
  • It is tempting to focus on which scale degree resolves to which scale degree (e.g. ti to do), but this does not provide a complete explanation.
  • Instead focus on the how each chordal member resolves in the progression. This should include the chordal member to which it resolves and the interval necessary to do so.
    • Try to discern which chordal members have multiple options and which seem locked into a specific resolution.
• What pitches are doubled? Are any omitted?

The next example focuses on a simple triadic progression and follows the circle-of-fifths backwards to add a ii chord. Does this follow the voice-leading explanation that you created after looking at the first examples? If not, how does it differ? After you have studied this, try creating a voicing for a vi chord that would precede the ii chord.

The next example adds the vi chord. Were you able to correctly construct this using your voice-leading rules? Is it more accurate to explain the voice-leading of the progression using chordal members or scale degrees? If you continue around the circle-of-fifths, what would the voicing for the next chord be?

Again, we ask the same questions. Were you able to correctly add the iii chord using your voice-leading rules? Is it more accurate to explain the voice-leading of the progression using chordal members or scale degrees?

Conclusions

As we look at implied harmony in two-voice counterpoint, we can demonstrate that simple voice-leading is all that is necessary to imply diatonic function. If we take that further, we should be able to create the fundamentals of harmonic progression using the voice-leading inherent in diatonic systems.

Beginning theory students often learn two general rules of thumb for voice-leading:

• ti resolves to do
• fa resolves to mi

This is helpful to begin thinking about voice-leading in the most basic of ways, but it only applies to a specific, albeit common, set of circumstances that arise in common practice harmony–the V⁷ to I progression. In contrast to those rules, look at the following two-voice outline of one of the most common progressions in tonal music.

In this common progression, the bass voice moves fa to sol, and it sounds acceptable to almost anyone’s ear. From this alone, you should infer that there is far more detail necessary to understand voice-leading.

So instead, you must base your general rules around chordal members and their resolutions, rather than scale degrees and their resolutions. Specifically:

• For chords that have roots separated by a P5:
  • The seventh of the first chord resolves to the third of the second chord.
  • the third of the first chord resolves to the root of the second chord.
  • If both chords are in root position, the bass voice moves from the root of the first chord to the root of the next chord.

Before moving on, take a moment to check these rules against the finished example from above, copied below for your convenience.

You can also alter this example to include seventh chords in order to apply the chordal seventh resolutions, but we will do that in the next topic.

Adding IV and vii^o

Beyond the iii chord, the voice-leading runs into an issue with harmonic function. While it is possible to continue this pattern through these two chords, in tonal harmony, the IV and vii^o chords actually function most often as if they are extensions of the ii⁷ and V⁷ chords respectively. Look at the following example to see voice-leading using both of these chords. The first measure uses the ii⁷ and V⁷ chords as part of a diatonic progression, but the second progression substitutes the IV for the ii⁷ chord and the vii^o chord for the V⁷ chord. After looking at this example, explain why IV and vii^o function similarly to ii⁷ and V⁷.

Please note that to demonstrate how closely related these chords are, many voice-leading rules of common practice harmony are broken in this example–most notably the parallel octaves between the soprano and bass between vii^o and I. This is for demonstration purposes only, do not assume that this is good voice-leading for IV or vii^o. We will discuss the rules of voice-leading in this style when we study part-writing in Units 10 and 11.

Conclusions

It is possible to continue our voice-leading pattern backwards to add the last two diatonic chords, IV and vii^o, but these chords actually function differently. Instead, the IV and vii^o chords function similarly to their two functional counterparts, ii⁷ and V⁷. The logic is fairly simple, if you remove the root from a ii⁷ chord, D-F-A-C in C major, you are left with a IV chord, F-A-C. Likewise, if you remove the root from a V⁷ chord, you are left with a vii^o chord. By this logic, the IV and vii^o chords often use alternative voice leading, because their tendency tones are not necessarily tied to the chordal thirds and sevenths.

When we add these to our harmonic progression flowchart, we get our basic outline for harmonic progressions.

(unnamed)	(unnamed)	pre-dominant	dominant	tonic
iii	vi	ii	V	I
		IV	viio

Using just this flowchart, you can build basic chordal progressions for a given melody by harmonizing the pitches with the correct progressions. Please note that the I chord can comfortably jump back to anywhere in the progressions.

Adding in Exceptions

There are a few common exceptions that should be added to this progression flowchart. We will discuss how these are used as we work through their appropriate topics (e.g. cadences, chordal substitutions), but for now, please add them to your list of possible progressions.

• chords that have the same function can move to each other
  • V can move to vii^o, and vii^o can move to V
  • ii can move to IV, and IV can move to ii.
• V can move to vi
  • This is most commonly used at the end of a phrase. In this case, vi is “replacing” a I chord and assuming a tonic function, so it must be used and voice carefully. See Unit 7c (later in this unit) for a full explanation of cadences.
• IV can go to I
  • This is most commonly used at the end of a phrase, and in this case, IV is “replacing” the V chord. This is another cadence, so it must be prepared properly. It is better to avoid using this progression in the middle of a phrase, so in your early attempts at part-writing, do not attempt to use this.
• UNCOMMON: vi can move to V
  • There are instances where vi will move to V, but in these cases, it is best to think of the vi chord as taking on a tonic function. In your early part-writing, do not use this progression, because like V moving to vi–a much more common progression–this progression is likely to result in poor voice-leading.
• RARE: iii can move to IV
  • It is difficult to use this without creating multiple voice-leading issues, so in your early attempts at part-writing, do not attempt to use this.

Changes in Minor

Minor follows all of the same progressions and exceptions, but the chord qualities change to match the naturally occurring pitches in the key signature. Please remember that minor keys must have a major V chord and diminished vii chord to function diatonically. This means that both of these chords are built using the raised seventh scale degree, even though this isn’t necessarily implied by the Roman numeral of the vii^o.

(unnamed)	(unnamed)	pre-dominant	dominant	tonic
III	VI	iio	V	i
		iv	viio