Goal
In part-writing exercises, the goal is to create smooth movement between harmonies while keeping the four voices relatively independent.
Smooth Movement Means:
- Step-wise motion dominates. (the bass exhibits more leaps, but still moves mainly by step)
- Common tones between two successive harmonies will usually be kept in the same voice.
- No large leaps (>5), except for bass. (the bass often leaps an octave down at cadences, and can leap a sixth down to move from tonic to first inversion tonic)
- No augmented melodic intervals. (augmented intervals within chords are fine, if the tones fit into the chord) Augmented intervals usually occur in minor keys, or with movement to secondary tonicizations (V/V, vii°/V, etc., where you have altered/raised pitches). Diminished melodic intervals are fine.
- In minor, always approach the leading tone from above. (this is related to the previous point)
Relative Independence Means:
- No parallel P8, P5, or their octave equivalents. This creates the impression that the voices are linked.
- Upper voice pairs (S-A, A-T) must remain within an octave of each other. Wide spacing (>8) creates separation into sub-groups.
- No doubling of tendency tones (the leading tone of the key, the root and fifth of any diminished or augmented triad, and the chordal seventh). Doubling these tones creates the impression that these voices will move in parallel, whether they do or not.
- Voices rarely cross (appear above or below adjacent voices) or overlap (move above or below where an adjacent voice was in the previous harmony). Crossing and overlapping confuse the listener’s perception of the melodic line for a particular voice. (two voices can double a note at the unison, but to avoid overlapping they must approach and leave the unison by contrary motion)
Chord spacing within a single harmony is usually an aesthetic choice, as long as other part-writing guidelines are being followed.
Doubling of chord tones should be thought of guidelines, except when dealing with tendency tones.
Part-Writing Goals in Practice
- Whenever possible keep common tones in the same voice, and move the remaining voices to the closest chord tone.
- Contrary motion between bass and upper voices will usually help you avoid parallel perfect intervals, and will reinforce independence among voices.
- Move by step whenever possible. Upper voices should generally avoid two successive leaps that do not outline a triad.
- Descend to the leading tone in minor.
- Choose your doublings to allow for the smoothest motion between harmonies (common tones and step-wise motion), assuming tendency tones are not involved.
- Generally double the root of root position major and minor triads, but not if it leads to part-writing problems. The same for the soprano of first inversion triads.
- Seventh chords in root position either do not have anything doubled, or have the root doubled and the fifth omitted.
- Seventh chords in inversion will always be complete, without anything doubled.
- It is not uncommon for the final tonic triad to have a tripled root and one third.
- It is very uncommon to double two separate chord tones (i.e., the root and the third are both doubled, with the fifth omitted).
- The chordal third must always be present.
Other Things to Consider
- When given a soprano or bass line, be careful whenever the soprano has a leap (large or small) in either direction, and whenever the bass leaps up. Downward leaps in the soprano and upward leaps in the bass can lead to voice overlaps. Upward leaps in the soprano can lead to spacing problems between soprano and
alto parts. Look at the given parts and plan ahead. (You usually can’t fix things just by changing one chord before the problem.) - Finally, check your work. Look at individual lines for augmented intervals. Notice how you approach and leave perfect intervals. Make sure leading tones are not doubled (including thirds of secondary V chords). Make sure that chordal sevenths are not doubled.
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