When you compose music voice leading is a skill you should at least know about. Modern jazz- and pop musicians don’t realy bother with it, but in the so called common practice period, which include the Baroque, the Classical and the Romantic era (1650 – 1900) there were specific ‘rules’ that had to be obeyed when connecting chords. Well, actually they were not rules but rather very strong directions.
You might think that because you are going to make a jazz– or a popsong you don’t really need to know this, but there is a good reason to keep paying attention. We are going to concentrate on the outer voices, i.e. the melody and the bass. The bass is also called the second melody, and basic knowledge of voice leading will help you to create a beautiful second melody.
The art of voice leading was based on the four part chorals of Johan Sebastian Bach (the most important Baroque composer).
1. Each of the four voices should move no more than necessary. They obey what Anton Bruckner called ‘the law of the shortest way’, and take the smallest possible step or leap. If two chords have a tone in common it should, if possible, be held over in the same voice.
2. No leaps larger than a fifth should be made, with the exception of the octave leap, whose effect is almost the same as that of repeating the note.
3. In the distribution of three chord notes among four voices it becomes necessary to double one of them. In the primary chords (I, IV and V) preferably the root is doubled. Sometimes the fifth can be doubled, but the third should not be doubled.
4. Also in II, III and VI the root is preferred; but in the first inversion of these chord the third should be doubled.
5. In VII the third should always be doubled.
6. Resolution of leading notes. In the classical period leading notes always resolved in the right manner: B – C, F – E, Ab – G.
7. Special precautions are necessary to avoid open or hidden parallel octaves or fifths. In the common practise it was understood that parallels just sound bad. However, popular and jazz music often contains voices moving in parallel octaves or fifths. They don’t care about parallels; they break the rules of classical part leading on purpose because the sound they are looking for is related to the much older folk music. We will discuss this in the next lesson. A hidden parallel occurs when two voices begin at different chord notes and move in the same direction to a fifth or octave. Hidden parallels often occur, they cannot be avoided. But they are least objectionable when the upper voice is the one that moves by step.
8. Chromatic lines should lay in one part.
These ‘rules’, by the way, only concern chord connection within a musical phrase. They don’t apply between the last chord of a phrase and the first of the next phrase, where there is no harmonic dynamics.
Incorrect voice leading
In the first example there is a parallel octave between bass and soprano; they both jump from C to F. Also there is a parallel fifth between the bass and the tenor. In the second example we see a hidden parallel octave between bass and alt, where the alt makes the biggest jump. Really, you shouldn’t do that!
Correct voice leading
In the first example we see a hidden parallel between bass and alto, which is OK if there is no alternative. The second example is much better; there are no parallels and the outer voices move in opposite directions. Also the third example is fine, although the common tone C is not held over in the same voice. This of course easily happens, depending on the melody-notes.
Exercise 1: Work out the following chord changes: I to IIm, I to IIIm, I to IV, I to V, I to VIm and I to VII- in C major. We strongly advise that you do these same exercises in other keys as well, beginning with F major and G major, and also that you work out these same exercises by choosing another spacing of the chord notes (close or open position).
The second melody
Now we are going to concentrate on the outer voices, i.e. the melody and the bass. The construction of the two outer voices is, as Schonberg wrote, of greatest importance. They should be the most variable voices, and contrary rather than parallel motion is recommended between these two. The bass is the ‘second melody’ and the interplay between melody and bass is one of the most beautiful and interesting features of many good compositions. To make a more interesting bass line, not only root positions of chords are used, but also the inversions. They add variety to the ‘second melody’ of the composition. Like the root chord a sixth chord for example is permitted anywhere (with the exception of the opening and closing chords which should appear in root position, and in almost all cases are I, the triad on the first degree). Only the root position and the sixth chord of a triad (for example C and C/E) are considered consonant, and if you use other chords they are considered dissonant and, like dissonant notes, have to resolve properly. The second inversion, the six-four chord (for example C/G), is such a dissonant chord; the fifth in the bass sounds to dynamic, it is not in rest; begs for a solution.
In the following two examples the V six-four; and I six-four chord; function as ‘passing-chords’. Notice that the outer parts move in opposite directions, which of course is excellent voice leading.
The I six-four-chord often is used as a ‘suspension-chord’ which resolves into V. It originated from the suspension of both C and E while changing from I to V. This became a real cliché in Baroque and Classical music.
The use of the 2-chord and its resolution is another well known cliché which is already around since the Renaissance. Remember that the V7 contains two leading notes; well, in this example we see the bass note F resolve to E in the I6 chord, while in the soprano the B resolves to C.
In folksongs and also in early choral music it was common practice to attach a chord to almost every new melody note, making the bass almost as interesting as the first melody. Johan Sebastian Bach was a real master of this. Actually the art of voice leading stems from his choral work. Here are some examples, in which we can see that actually all four voices are melodies; they all contain some simple non chord notes like passing notes and auxiliary notes (which are all coloured red).
Two chorals from the Mattheus Passion BMV 244, J.S.Bach.
Check that only hidden parallels occur in the two chorals. Notice in both chorals that at the end the leading note jumps down to the fifth of the tonic chord (in the first F# to D in the alto; in the second C# to A in the tenor). Notice also the crossing of alt and tenor in bar 2 of the second choral. This is a good illustration of the fact that the voice leading directions can be easily exceeded when you have a good reason for it.