APPENDIX A: VOICE LEADING OVERVIEW
Introduction
Tonal music (and to some extent pre-tonal music and some 20th century music) is made up of an interaction between surface voice leading and underlying patterns of root progressions. This website is based on original research which explains the nature of this interaction and how underlying root progression patterns form musical phrase structures.
Tonal music is not just a series of block chords but involves individual voices or parts moving through the harmony. These form the melody, the bass and middle voices. These voices flow through the underlying harmonic structure and each is in counterpoint with the other voices. The movement of these voices is governed by the principles of voice leading. These interactions are important not just in classical music but also in popular and other 20th century music.
In order to understand the underlying root progressions, it is necessary to first strip away the surface voice leading. The purpose of this stripping away is not to ignore the surface voice leading, but in the process of analysing the surface, to understand how it contributes to the motivic and melodic elements of the music. These analyses also reveal aspects of the voice leading and root progression patterns which contribute to the period, style and mood of the music.
By removing the surface voice leading, we reveal the underlying chords. However, when the obvious surface detail is removed, some of the remaining chords are still the result of voice leading. These include auxiliary chords, passing chords, appoggiatura chords and linear progressions. These also have to be removed in order to reveal the underlying structural root progression patterns.
In contrast to the patterns in root progressions, the principles of voice leading are relatively well understood, but for those readers not fully familiar with the this topic, this section summarises the main principles. Most of the rest of this website is about how root progressions work.
Voice leading is sometimes referred to as part writing. Either term refers to those principles which describe the way vocal or instrumental parts move from one note or chord to another taking into account the interaction between individual parts and with the underlying chord progressions. Voice leading is a subset of, and is described by the rules of, counterpoint. However, the term counterpoint also includes other topics such as imitation, fugue etc that go beyond the scope of this appendix. For simplicity, I will use the term voice leading in the rest of this section.
In this appendix, I will take an historical view of the subject, since it is necessary when analysing a piece of music, to know how the voice leading patterns work for the period or genre of music in question. This variation in voice leading patterns is usually overlooked but an understanding of these changes is vital for a style sensitive musical analysis. I will start with a summary of the 16th century principles of voice leading and then show some of the important historical changes that have taken place after that period including two examples from the 20th century. The full analyses in Chapter 8 will show how voice leading interacts with root progression patterns for different genres of music. This appendix can be used as an introduction to these full analyses and is best used in conjunction with that chapter in order to fully understand the analyses.
A good starting point in understanding these principles is to study 16th century polyphony. Here the individual voices move independently against each other. In this type of music, voice leading is more important than root progression patterns. Partly because of this, and partly because the main principles of voice leading were consolidated during this period, this forms a good starting point for the understanding and study of voice leading, Many theory books describing voice leading were written during and just after this period. See bibliography (Zarlino, Fux etc).
Whilst the rules of voice leading were extended/relaxed after this period the main principles, nevertheless form the basis of all voice leading after that period in tonal and tonally based music. The formal study of voice leading of this period is often made by reference to the teaching method referred to as species counterpoint. Whilst species counterpoint does not fully describe all aspects of 16th century polyphony it does form a useful introduction to some of the main principles of voice leading, even if it does normally focus on 2 part writing. A full understanding of the music of the period also requires study of the texts of the period and listening to performances of the music but I will use ideas from species counterpoint as an aid where it is useful.
In 16th century polyphony, the underlying principles that govern all voice leading can be summarised as follows:
- The note by note movement of each voice.
Parts should normally proceed to the same note or by step to an adjacent note with occasional leaps to create variety and facilitate the counterpoint.
- The correct use and interaction of consonance and dissonance.
All intervals are defined as either consonant or dissonant and whilst consonant intervals can be used freely, dissonant intervals can only be used according to strict rules. Structurally important note combinations are always consonant and dissonance is reserved for elaborating underlying structural consonances.
- The concept of the independence of the voices.
According to this principle, the voices make the best counterpoint if they move in rhythmically and melodically independent ways. Thus certain types of parallel motion are avoided.
The importance of these principles cannot be overstated. They form the basis of all voice leading in tonal and tonally influenced music, both in classical and in popular music. This includes to varying degrees, pre-tonal music and tonally based music of the twentieth century. What differentiates each period or genre of music is the way the detailed rules of voice leading are extended or changed in various ways. These changes are accompanied in similar ways, by changes in chord syntax and root progression syntax.
In this section I can only summarise voice leading and its history in overview, as this is not primarily a website about voice leading or counterpoint but rather about root progression syntax and musical phrase syntax. After reading this appendix, the reader is encouraged to study the subject in more detail by reference to the books and other resources indicated in the bibliography.
Next Topic: Consonance and Dissonance