APPENDIX A: VOICE LEADING OVERVIEW
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 how these underlying root progression patterns work and shows how they form musical phrase structures.
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.
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 contrast to the patterns in root progressions, the principles of voice leading are relatively well understood and so most of this website assumes that the reader is familiar with these, 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 10 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.
Most of this book assumes that the reader knows how to remove the surface voice leading, revealing 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 and appoggiatura chords. They also have to be removed in order to understand the structural root progression patterns. These types of chords have been included in the discussion that follows.
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 after this period the main principles defined then, 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 are:
The importance of these principles cannot be overstated. They also 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