Music theory is usually taught by dividing ‘music’ into different topics: harmony, melody and counterpoint, composition, analysis etc. This is often the most efficient way to tackle such a vast subject, and can be an effective means of focusing on different areas. What needs to be kept in mind, however, is that there is considerable overlap between these areas. As an example, guitarists usually divide their practice time into playing licks (melody) and playing chords (harmony). In this way the two are often separated into the vertical aspect: chords – where the notes are stacked on top of each other and played together, and the horizontal: melody – where the notes follow each other and are played separately. There is nothing inherently wrong with learning this way, however, as was mentioned previously, there is often considerable overlap between different areas of music and the overlap between harmony and melody is often greater than most people realise. Consider the following,
In this example most people still recognise the sound of the familiar perfect cadence, dominant to tonic (V – I) in G major. The ‘pull’ of the dominant to tonic is still present even though temporally there is a great distance between the chords. Clearly, however, there is no direct relationship between any notes in the D major chord and the notes of the G major chord; our ear simply accepts the relationship because the move from V to I is so common.
How about in this example?
We can hear, and see, there is a closer relationship between these two chord shapes. While the chords in example one were temporally distant, those in example two are closer together. Many people accept this concept but still consider the two chords as separate vertical entities; which they are. But if we look, and listen, closely we begin to realise that the chords aren’t simply two vertical stacks of notes which move from one vertical position to another, there is certain melodic movement which also occurs between these chords. Notice, for example, the leap from the root of the D major chord to the root of the G major chord, the downward move by step of the As in the D chord to the Gs of the G chord, the rise of the F sharp of the D chord to the G of the G chord, and how the Ds of the D chord tend to remain in the same position when the G chord is played.
This is Voice leading. Voice leading occurs to a greater or lesser extent any time chords follow each other in a progression (Voice leading occurs between any chords, however, for the purpose of explaining the basic movements involved only dominant-type chords moving to tonic will be used in this article).
By simply learning standard chord shapes and moving them from one to the next without regard to how the chords are actually moving it is easy to lose track of this concept. After all, the chords in example one are still technically D major and G major chords which form a perfect cadence, but they don’t sound as connected as those in example two, which are also standard chord shapes but their progression involves voice leading. Guitarists who appear to play more intricate chords often construct their chord shapes, and progressions with voice leading in mind.
Let us expand on some of the voice leading concepts found in example two. Often a note will possess more than one potential move between its own chord and another. An example of this can be seen with the D root of the D major chord, which moves to the root of the G chord but also remains in the same position to sound as the fifth above the G chord’s root. The same can be seen with the D note an octave above the D chord’s root. This D note also remains in the same position but also moves to the B note, the third of the G chord. Multiple moves for notes frequently occur when the texture increases, as in example two, or decreases.
The essential voice leading of example two is summarised in example four.
The third (F sharp) of the D chord, is also the leading note in the key of G major and, as the leading note,it tends to move to the root of the key (G); the fifth (A) of the D chord tends to move down by step to G; and the root of the D chord either remains in the same part, moves to the root of the G major chord, or moves to the third (B) of the G chord.
Voice Leading of the Dominant Seventh
If we change our dominant into a dominant seventh
The same basic movements occur. Note, the seventh of the D major chord (C) moves down to the third of the G chord. The seventh and leading note (C and F sharp respectively) are called Tendency tones, as they have a tendency to move in specific directions: the seventh down by step, and the leading note up by step. The two tendency tones in a dominant seventh also form a tritone which has a strong pull towards the root and third of the tonic triad.
Even when the dominant seventh is inverted
the same movements occur. When only the tritone is played there is a strong enough pull towards the tonic, which is why the fifth, and even the root, of a dominant seventh is often omitted in extended dominant chord voicings (Guitarists often omit the root of a chord as many times the bassist will be playing this note).
If we play only F sharp, C and E, as we would find in a G9 chord with the root and fifth omitted,
the pull towards the tonic is still enough for us to accept this as a dominant chord. Voice leading of extended chords will be the topic of another article.
Voice Leading of the Diminished Triad and Diminished Seventh
The diminished triad, diminished seventh and half diminished seventh chords can be included in the dominant family of chords when they are found on the vii degree of a scale. This is because, like the dominant chords, they typically move to the tonic.
The diminished triad is typically found, or used, in first inversion.
Here, the tritone is still resolved correctly while the third of the diminished triad, in this instance, moves to the root of the tonic chord.
When we add a diatonic seventh to the diminished triad in a major key we get a half diminished seventh chord (see Creating Seventh Chords). When a seventh is added to a diminished triad it can be used in any inversion.
In root position the root of the half diminished seventh still rises while the other notes tend to by fall by step.
In first inversion the same voice leading tends to occur
In second inversion the same voice leading occurs except, in this example, the third of the half diminished seventh (A) moves up instead of down. This results in a doubled third (B) of the tonic chord. As with all theory, there will always exceptions to the rules, for this reason it is important to learn the rules but use them as a guide rather than a rigid framework.
In third inversion
the notes resolve as with the root position and first inversion.
From these examples you will notice the chord shapes which occur when voice leading is considered. Many of these are not the standard forms which most guitarists tend to use, but the sound which results from their use is more coherent and smoother.
When a diatonic seventh is added to the diminished triad on the seventh degree of a minor key we get a diminished seventh chord. As with the half diminished seventh chord the diminished seventh chord can be used in all inversions. The voice leading tends to follow that of the half diminished seventh; the most important resolutions to consider are the rise of the root of the diminished seventh (the leading note) and the fall of the seventh of the diminished seventh.
As we saw also with the half diminished seventh chord, the third and fifth of the diminished seventh chord may sometimes rise or fall depending on the context – this can mean sometimes even the tritone doesn’t resolve correctly.
Consider the following
Here the tritone (F sharp – C) doesn’t resolve to G and B flat, as it typically tends to. However, because the lowest and highest notes of each chord rise, and the diminished seventh chord is framed by two inversions of the same chord, our ears accept this resolution. Also, within the rising progression the G – F sharp – G, and D – E flat – D voice leading, which correctly resolves the leading note and seventh of the diminished seventh, also guides our ears through this progression.
Voice leading is an integral part of most music. Even a basic understanding of the rules governing the movement between chords can give a sophistication to your progressions and your compositions as a whole. As with all theory, these examples should be practised in all keys and different fingerings should be used so that a deeper understanding of the sounds and concepts presented can be gained.