Basic Concepts of Four-Part Writing
As we begin our work in four-part writing, there are some fundamental principles that must be established from the outset. These fall into four categories: 1) the basic voice ranges, 2) the ways of voicing three notes into four voices, 3) the connection between the rules of 2-part counterpoint and the procedures of four-part writing, and 4) the concept of four-part writing as a integration of four simulataneous melodies.
We'll take up each topic in turn.
Basic voice ranges
In writing for four voices, we refer to them by their traditional vocal ranges, that of soprano, alto, tenor and bass. Centuries ago, their voice parts were written in their own clefs, with the upper three voices indicated by the placement of the middle C, and the bass voice placed on the F clef. This orginally looked as followed.
Here, the bottom line is C in the soprano clef, it's the middle line in the alto clef, and it's the second to the top line in the treble clef. Through this system, most of the notes associated with each voice fit primarily on the staff, with fewer uses of ledger lines above or below.
In older times, musicians routinely knew these four clefs. But since the mid-19th century, most musicians learned their music through the piano. It thus became commonplace to train musicians solely through the treble and bass clefs. Thus the four clefs, which in many ways are more logical than only two, were nevertheless reduced to only two, with the treble clef used for both the soprano and alto voices, and ultimately for the tenor voice as well, notated an octave higher than sounding. (Formally, the tenor line should have a little "8" under the treble clef, as below to indicate that the music should be read down on octave, but often this is simply assumed and thus left out of printed music.)
As to voice ranges, we think of the following as normal ranges for the four voices.
These ranges are useful, because if you learn to write well for the four standard voice ranges, they can apply quite readily to instrumental writing also. For example, the ranges of the voice are roughly equivalent to the ranges of a string quartet (although the violin can range considerably higher than the high A), and similarly you will gain good habits in writing for brass instruments and woodwinds.
"Voicing" triads for four voices
When writing for four voices, a basic principle must be observed. This principle is based on the the natural resonance of the overtone series.
When you contemplate the overtone series, you will notice a natural expansion of intervals towards the fundamental and a natural gathering together of intervals towards the higher partials.
This is the principle upon which four-part voicing is based. In brief, keep a greater distance between the bass voice and the upper voices, and keep the upper voices closer together. The lower the bass voices descends, the greater the distance there should be between the bass and the upper voices.
As a general rule, simply do the following:
- Be certain that the soprano and alto voices are closer than an octave to each other. Typically, allow no more than a sixth between the two.
- Do not allow the tenor voice to stray lower than a seventh below the alto, and again, typically, no more than a sixth.
- The bass voice may range freely. When it is closer to the tenor, then the alto and soprano should not range too far away. Think in this case that the bass represents the second, third or fourth partial. The upper voices are relatively close to the lower voices.
- When the bass ranges away from the tenor voice — and it is perfectly OK for the bass to be a tenth or even a twelth away — there is a greater ability to expand out the voices, as in the model of the harmonic series.
Observe the following expanded voicing. As the bass ranges farther from the tenor, there is greater freedom for the upper voices to expand. When the expansion becomes great, it is typical for the soprano to split into soprano one and soprano two. When the voices spread out even farther, some of the other voices may also double so as to avoid great distances between the voices.Those who have sung in choirs will have observed this phenomenon.
Doubling Voices
The other basic princple of four part writing concerns the distribution of three pitches across a four-voice texture. Unless you are introducing the seventh of a chord (most commonly the dominant seventh, occasionally the minor seventh), you will be voicing a triad and will need, logically, double one of the pitches. Here is the basic principle, recognizing that exceptions are often to be found within certain harmonic contexts.
1. Root position triads. Double the root
of the chord, which is the same as saying double the bass note.
2. First-inversion triads. Double the soprano, regardless
of which voice it represents.
3. Second-inversion triads. Double the bass, which is the
same as saying double the fifth of the triad.
4. First-inversion diminished triads. The diminished triad
appears most often with the third in the bass, so as to avoid the tritone
between the actual root of the chord and the upper fifth. When voiced in
this way, double the bass note, which is the same as saying double the third.
Thus the tritone is only represented by one voice, and the more stable third
is represented by two.
5. Seventh chords. Regardless of inversion, distribute the
four notes of the seventh chord, of any type, to the four voices, observing
smooth voice leading. Occasionally, especially with the dominant seventh
chord, the fifth can be omitted and the root doubled.
The following examples apply whether the chord is in major or minor (thus, imagine these both in C major and in C minor, with the key signature of three flats).
Further considerations about four-part voicing will be discussed in detail in chapter 5.
2-part Counterpoint and 4-Part Tonal Writing
Some of the fundamental practices that you learned doing two-part counterpoint will apply to your four-part writing. Most significantly, you will observe the following:
- Avoid parallel octaves at all costs! Parallel octaves, that is, two
voices moving in octaves in the same direction to the same note, complete
destroy a sense of independence between the voices.
- NOTE: this principle does not apply in the case of orchestation. When writing for orchestra or large jazz ensemble, often voices will doubled at the octave, moving in parallel motion with voices above or below. Still, within the context of voice leading, the same principles still apply.
- Avoid parallel fifths as well! Since perfect fifths are in ratios of 3:2, they are close enough to the ratio of 2:1 as to sound almost indistinguishable when moving in parallel motion. Thus, parallel perfect fifths are completely avoided in four-part writing.
- Direct motion into an octave or fifth, as in two-part counterpoint, is also to be avoided. There are, however, exceptions to this rule. This will covered in chapter 5A, which delves into the rules of four-part writing in greater detail.
- Parallel thirds and sixths are always good, just as in two-part modal writing.
- Perfect fourths may move in parallel motion when accompanied by a third moving in the same direction. Commonly, this will occur when a triad is in first inversion and moves to another triad in first inversion.
- A balanced combination of parallel, contrary and oblique motion between all voices is the fundamental goal of good four-part writing.
- The treatment of dissonance has its basis in the techniques learned
in 2-part species counterpoint:
- Certain notes may be suspended from a previous harmony that are dissonant to the new harmony, and then resolve (typically downward) into a chord tone. Thus the movement that we practiced in two-part writing, that of the 9-8, 7-6 and 4-3 suspension, easily finds its way into four-part writing.
- Dissonances may be sounded on a strong beat as long as they are immediately resolved into a chord tone. This is phenomenon of the appogiatura, or "leaning tone."
- These and other treatments of dissonance will be covered in greater detail when we analyze Bach chorales and then when we apply these principles to the more advanced stages of chorale writing.
Four Melodies, Interacting
Ultimately, a final lesson must be taken from our brief work in 2-part writing: counterpoint is the combination of melody, one against another. Four-part writing adds to this the conscious knowledge of harmonic progression, but within this harmonic progression, individual voices are nevertheless singing (or playing) well shaped melodies. Four part writing, for all that we will focus on the vertical elements of the harmonic structures, remains the interaction of four melodies which happen to also form vertical harmonies. We will see this again and again when we look at the chorales, presently, of J.S. Bach.