Following are the “rules” of voice leading when writing in Bach style chorales (SATB style).
The Basic Rules of Part-Writing:
Rule 1: Use the correct notation.
Rule 2: Double the stable tone.
Rule 3: Maintain the individuality of the voices.
Rule 4: Move to the nearest chord tone in contrary or oblique motion to the bass.
Rule 5: Move tendency tones in the direction of their tendency.
Sometime the rules are broken, but you must first learn what is normal before you can break the rules.
Use the correct notation.
Notate the Soprano (S) on the treble clef staff with stems up.
Notate the Alto (A) on the treble clef staff with stems down.
Notate the Tenor (T) on the bass clef staff with stems up.
Notate the Bass (B) on the bass clef staff with stems down.
Chords may be in open or close spacing.
Chords are in close spacing when no chord tone can be placed between the SA or AT voices.
Chords are in open spacing when you can put another chord tone in between the S and A and/or between the A and T voices.
Double the stable tone.
ROOT POSITION TRIADS
In root position triads, double the root (the most stable tone).
EXCEPT:
In diminished triads, double the 3rd (not a note of the tritone).
In V-VI in minor keys, double the 3rd of the VI chord.
FIRST INVERSION TRIADS
In first inversion triads, double a stable tone. OR: double the soprano. OR: double the 1, 4, or 5 scale degree.
In the example below: In the viio6 chord, the D is doubled since the other two notes in this chord (B and F) form a tritone – a very unstable interval. In the I6 chord, the C, the tonic or scale degree 1, is doubled; this note is also the soprano tone in the chord.
In the example below: In the ii6 chord the third of the chord, the bass and scale degree 4, is doubled. In the V6 chord, the G, scale degree 5, is doubled.
SECOND INVERSION TRIADS
Remember that second inversion chords will appear in one of 4 ways: as cadential (I64-V), pedal (I-IV64-I), passing (I-V64-I6), and arpeggio (I-I6-I64) 6/4 chords.
In second inversion triads, always double the bass.
NEVER DOUBLE LEADING TONE
Never double the leading tone. When both resolved to tonic, it creates parallel octaves.
INCOMPLETE TRIADS
In Incomplete triads, triple the root, include the third, and omit the fifth.
In the example below, the I chord is incomplete; it has 3 roots (C) and 1 third (E).
INCOMPLETE SEVENTH CHORDS
In Incomplete seventh chords, double the root, include the third and the seventh.
In the following example, the V7 chord is incomplete; it has 2 roots (G), 1 third (B), and 1 seventh (F).
Maintain the individuality of the voices.
Keep the voices in their proper ranges.
The maximum distance between S and A and A and T is a P8.
The maximum distance between T and B is 2 P8s.
Do not cross voices in the same chord or overlap voices between two adjacent chords.
Use contrary or oblique motion to the bass more frequently than similar motion. Use parallel motion only when necessary.
* Contrary motion — voices move in opposite directions.
* Oblique motion — one voice remains on the same note while the other voice moves.
* Similar motion — voices move in the same direction by different intervals.
* Parallel motion — voices move in the same direction by the same interval.
NEVER write parallel P1, P5 or P8. (Parallel 5ths shown below.)
Move to the nearest chord tone in contrary or oblique motion to the bass.
Use conjunct motion (stepwise) as much as possible.
Do not leap in a voice (melodically) more than a P8. Try to limit leaps in the soprano to a M6, in the tenor and alto to a P4.
Do not leap twice in the same direction unless outlining a triad.
Don’t write hidden octaves or fifths. Don’t move in the same direction in the outer voices (soprano and bass) and by leap in the soprano to an octave or a fifth.
Don’t use augmented or diminished intervals melodically.
Move tendency tones in the direction of their tendency.
Resolve active tones in the direction of their tendency.
The leading tone in the Soprano or Bass must resolve to tonic.
In an inner voice, it may resolve down to the 5 (frustrated leading tone).
Resolve sevenths of chords down by step. Resolve the 7th of a V7 down by step.
Resolve tritones as follows: A4 will resolve out, d5 in.
It is OK to move from a P5 to a d5 (unequal fifths), but not from a d5 to a P5 (the tritone doesn’t resolve).
Altered notes: If note is raised, continue going up. If note is lowered, continue going down.
Chromatic movement of a note: Keep chromatic movement of a note in the same voice; don’t write cross relations especially between the outer two voices.