4.2 SATB Voice Leading

Raise your hand if you are a soprano!

Raise your hand if you are a tenor! 

Don't know yet? Not a problem. However, it will be helpful to get to know your voice range if you haven't already. On the AP Music Theory test, you will need to sing for some of the FRQs and also be able to transpose a written piece of music into your range. If you haven't done much singing before, it's time to start clearing out those cobwebs in your vocal chords!

Musical lines, whether in instrumental or vocal pieces, may be described using the vocal parts: soprano, alto, tenor, bass. This is called SATB, for short. These are the four main vocal parts in choral music. The soprano is the highest vocal range, followed by the alto, tenor, and bass, which is the lowest vocal range. 

In choral music, these four vocal parts are typically written in four-part harmony, meaning that each part has its own unique melody that is harmonized with the other parts. The combination of these four parts creates a rich and full sound that is characteristic of choral music.

In SATB (soprano, alto, tenor, and bass) vocal music, voice leading refers to the way that these four vocal parts move in relation to each other. Good voice leading can help to create a smooth and harmonically interesting texture in a composition, and it is an important aspect of music composition and arranging.

When we examine a composition in four-part harmonies, we will also be using the SATB texture to complete a Roman-numeral Analysis. This means that for each chord in the harmony, we want to figure out which diatonic chord and which inversion it is in. 

Realizing a figured bass refers to the process of interpreting the harmonies indicated by the figures in a figured bass notation and turning them into an actual musical realization, either by playing or singing the chords indicated by the figures or by transcribing them into standard chord notation. 

Figured bass notation was commonly used during the Baroque period to indicate the harmonies that should be played or sung in a composition, but it did not specify the exact voicings or melodies for the individual parts. Therefore, realizing a figured bass involves making creative decisions about how to voice the chords and which notes to use in each voice, based on the harmonies indicated by the figures.

Realizing a figured bass can be a complex process, as it requires a good understanding of harmony and the ability to make musical decisions that will work well within the context of the composition. However, for the purposes of AP Music Theory, you should try to follow all of the voice leading rules that you are given. 

We’ll introduce some voice leading rules in each chapter – there are a lot that we have to cover. In the last chapter, we went over rules for writing the soprano line (the top line of the music) and the bass line (the bottom line of the music). As a review, here are those rules: 

For the soprano line, here are a few things that you should keep in mind: 

1. Voice leading should proceed mostly by step without excessive leaps.
2. When possible, pitches common to adjacent chords, or common tones, should be retained in the same voice part(s).
3. For clarity of voice leading, any chord should maintain soprano-alto-tenor-bass (SATB) order from high to low to avoid voice crossing.
4. If a perfect fifth between two voices is not immediately repeated, it should proceed to an interval other than another perfect fifth between the same voices. This applies to parallel motion (i.e., parallel fifths) as well as contrary motion; it also applies to nonadjacent chords on successive beats.
5. If a perfect octave or unison between two voices is not immediately repeated, it should proceed to an interval other than another perfect octave or perfect unison between the same voices. This applies to parallel motion (i.e., parallel octaves) as well as contrary motion; it also applies to nonadjacent chords on successive beats.
6. All voices should proceed melodically with the following intervals—major and minor second, major and minor third, perfect fourth, and perfect fifth. All melodic augmented and diminished intervals should be excluded, as they produce uncharacteristic dissonances. All melodic intervals larger than a perfect fifth should also be excluded, as they create uncharacteristic disjunct motion.
7. The leading tone in an outer voice (i.e., soprano or bass) should always resolve up by step to avoid an unresolved leading tone
8. Outer voices may include leading tones as long as those leading tones are not doubled in another voice and resolve to the tonic by ascending in stepwise motion, to avoid an unresolved leading tone.

And, for the bass line, we have: 

1. All implied chords must allow the corresponding soprano notes to make harmonic sense.
2. An acceptable harmonic progression can be made using tonic, supertonic, subdominant, and dominant triads exclusively, as long as the normative procedures of harmonic progression are followed.
3. Repeated instances of a specific harmony— that is, repeating a particular chord in a particular position (root position or inversion)— are acceptable only if the repeated harmonies start on a strong beat. However, at the beginning of a phrase, the repeated harmonies may start on a weak beat.
4. Melodic interest in a bass line may be created by balancing upward and downward motion and by balancing melodic steps and leaps.
5. A bass line uses melodic leaps with greater frequency than upper voices or parts, which tend toward more stepwise motion.
6. Allowable leaps include thirds, perfect fourths and fifths, sixths, and octaves, and, if resolved properly, descending diminished fifths.
7. Octave leaps should be followed by changes in direction.
8. The bass line may include successive leaps in the same direction as long as the pitches outline a triad.
9. Repeated bass notes are acceptable only if they start on a strong beat. However, the repeated notes may start on a weak beat if it is the beginning of a phrase or if the second note is a suspension.
10. Although bass lines may feature note values ranging from half notes to eighth notes, the quarter note is the most frequent rhythmic value

Doubling Rules 

Now, it’s time to add a few more rules. Introducing… doubling rules! When you are writing a four part harmony, you will have to double (aka reuse) one note for triads, since triads only have three notes. Sometimes, you also might double the notes from a seventh chord, if you choose to exclude one note from the chord. Here is how you should pick which tone to double:

1. Double the root of a triad whenever voice leading allows.
2. Thirds and fifths may also be doubled in triads when they result in good voice leading.
3. In all situations, always double non-tendency tones (i.e., tones other than the leading-tone and chordal seventh).
4. If the fifth is omitted in a root-position seventh chord, double the root. § Following a complete root position V7, the tonic triad may have three roots and a third (no fifth).
5. In 6/4 chords, always double the bass

What is a tendency tone, you might ask? A tendency tone is a tone that should always be resolved a certain way. For example, the leading tone should always be resolved up to the tonic, and the chordal seventh (the seventh in a V7 chord, and the 4th on the diatonic scale) should always be resolved down to the 3rd. 

One more rule for doubling: don’t exclude any tones for inverted chords! 

...And Some More Voice Leading Rules 

Intervals Between the Voices 

Remember when we talked about parallel fifths and parallel octaves between the outer voices? This also applies with inner voices: try not to have fifths or octaves between any of the voices. These are called direct fifths and direct octaves. 

Additionally, if outer voices move to a perfect interval by similar motion, the upper voice should proceed by step. 

And, just like you shouldn’t have two parallel fifths or octaves between voices, you also should avoid three parallel thirds or sixths between voices. 

Finally, you should avoid something called unequal fifths. This is where a diminished fifth resolves to a perfect fifth. Most of the time, you should resolve a diminished fifth to a third. However, one exception is that you can use rising unequal fifths in a I - V 4/3 - I6 chord progression. 

These rules are designed so that you vary motion of the voices: we don’t want one voice to be a copy of the other voice but just a third higher. 

Spacing Between the Voices 

The most important rule about spacing of the voices is that you shouldn’t let the ranges of the voices cross! For example, if the highest note in the tenor voice is a high B on the bass clef, then the lowest note on the alto voice should be no lower than middle C. 

How big should the ranges be? Generally, for any chord, the spacing between the three upper voices (soprano, alto, and tenor) should be less than an octave. However, there can be a bigger spacing (and a bigger range) for the bass voice. 

🦜 Polly wants a progress tracker: Which voice part is typically a higher male voice? Which voice part is typically a lower female voice?