Part Writing

Stylistic Practices

Root Position

• When the two roots lie a P4 or P5 apart (one common tone):

• Keep the common tone and move the remaining two upper voices stepwise to the chord tones of the next triad.

• Do not keep the common tone, especially when the soprano descends scales steps 2 to 1. Move all three upper voices in similar motion to the nearest chord tone. If handles correctly, the roots will be doubled.

• When the two roots lie a 3^rd apart (two common tones):

• Keep both common tones and move remaining upper voices stepwise. If handled properly, the roots of the two chords will be doubled.

• When the two roots lie a 2^nd apart (no common tones):

• Move the three upper voices in contrary motion to the bass, making sure that each voice moves to the nearest chord tone of the next chord. If handled correctly, the roots of the two chords will be doubled. An exception is the progression V-vi/VI. In this case, double the 3^rd of the vi/VI triad. Only two upper voices will move in contrary motion to the bass.

• When chords are repeated:

• Maintain proper doubling, range of voice, and keep the usual order of voices. But otherwise, freedom to exchange chord factors among voices is acceptable. Sometimes a change in position takes place.

First Inversion Triads:

• Double any triad factor that facilitates smooth voice leading. Favoured notes are the soprano (most often) and the bass (less often). Never double the leading tone. Observe general recommendations regarding voice ranges, order and spacing.

Voice leading for the vii⁶ :

• Double the third (bass note) or the fifth. The bass note is preferred. Move all voices with as much stepwise motion as possible. Avoid skips of a tritone.

Voice leading for the ii⁶ in minor keys:

• Double the bass note (third) or the root (in an upper voice). When approaching or leaving the ii⁶, make voice leading stepwise wherever possible and avoid melodic tritones.

Voice leading for ⁶₄ chords:

• Except under unusual circumstances, double the bass note (fifth).

• Approach and depart with as few skips as possible.

• In only the arpeggiated ⁶₄ chord is the bass note approached or left by skip.

• Use only the four types of ⁶₄ chords described here: cadential, passing bass, arpeggiated bass and pedal bass.

Unstylistic Practices - Inviolate

• Avoid parallel perfect Octaves, fifths, or perfect unisons. Successive perfect intervals containing the same pitches are not considered parallel.

• Never double the leading tone (7^th) of the scale.

• Do not write pitches out of the range of that particular voice. Keep all voices within their range at all times.

• Avoid the melodic augmented 2^nd and 4^th in all voices.

Unstylistic Practices - Occasionally Broken

• Avoid crossing voices. On rare occasions, crossing of voices is justified only if it improves voice leading.

• Spacing between adjacent voices should not exceed an octave in the three upper voices. The spacing between tenor and bass can be of any reasonable interval (never greater than two octaves).

• Do not overlap adjacent voices more than a whole step. An overlap occurs between two chords when one voice moves above or below the previous pitch of an adjacent voice. Overlaps of a half- or whole- step may be employed if it improves voice leading.

• Do not move in the same direction to perfect intervals in the two outer voices. Such motion is perceived by the ear as parallel perfect interval.

• Unequal 5ths (P5^th s to d5^ths or v.v.) Ore found in chorale harmonizations and may be used sparingly. The progression ofvii⁶-I, under certain circumstances, requires the use of unequal 5^ths.

• Melodic augmented 2^nds and 4^ths are almost never found in chorale literature of the 18^th-century.

• The melodic descending d5^th appears sometimes in bass voices, but rarely in the soprano.

• The d4^th is a diatonic interval in the harmonic minor scale (from the 3^rd down to the 7^th), and may be used in isolated situations.

• The leading tone should progress upward to tonic when in an outer voice and is least commonly applied in the bass.

Other Special Considerations
Augmented 6^th chords:

• Built on the Major 3^rd below the tonic of the key

• Italian 6^th (It⁶) - Major 3^rd + Augmented 6^th (total of three notes), Resolves outward to V orV⁷directly, or through I⁶₄.

• French 6^th (Gr⁶) - Major 3^rd + Aug. 4^th + Augmented 6^th (four notes), Resolves outward to V orV⁷directly, or through I⁶₄.

• German 6^th (Fr⁶) - Major 3^rd + P5^th + Augmented 6^th (four notes), Must resolve to V through I⁶₄ to avoid parallel 5^ths.

Neapolitan 6^th chords:

• Major triad built on the lowered 2^nd scale degree. Resolves inward to V⁷ or cadential I⁶₄ chord.

• Double the bass (3^rd of the chord) whenever possible. Melodic d3^rd in soprano considered desirable.

• Avoid chromatic voice leading.

• When going to I⁶₄, avoid the parallel 5^ths; instead, invert them to 4^ths.
  

Borrowed chords:

• Chords borrowed from the relative mode, used as colour.

• Avoid doubling the altered notes.

• Bass note moves upward, other voices in oblique or contrary motion.

• Rule of thumb: follow general guidelines as they appear in the key from which the chord was borrowed. (e.g. The Picardy 3^rdfollows rules from the parallel major key.)

Altered dominants:

• Dominant or secondary dominant triads or 7^th chords with a raised or lowered 5^th.

• Resolve the altered 5^th in the direction of the alteration.

• If a 7^th chord, resolve 7^th down one scale degree. (This may result in a doubled 3^rd or a tripled root)

• Never double the altered 5^th.

Chromatic mediants:

• Altered mediant or submediant triads (occasionally 7^th chords).

• Since reached and left through 3^rd relationship, chromatic movement is common.

• Double the root whenever possible.

Secondary dominant and leading tone chords:

• Use standard voice leading practices: Double the bass note (the 3^rd), avoid the melodic tritone, move as stepwise as possible and resolve tritones in the direction of their spelling (inward if d5^th , outward if A4^th).

Info synthesized from:

Benward, Bruce and Gary White. Music in Theory and Practice. Ed. Kathleen Nietzke et al. 5^th ed. Madison, Wisconsin: Brown and Benchmark Publications, 1993.

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