Chapter 6- Root Position Part Writing
There are 4 different intervals that can separate the roots of any 2 chords (Due to the inversion of the intervals:)
1. Same roots (repeated chords)
2. 4th Apart (5th)
3. 3rd Apart (6th)
4. 2nd Apart (7th)
REPEATED ROOT RULES:
A. 4 PART TEXTURE
a. All members of triad usually present.
b. Root is doubled. Leading tone 7 should NOT be doubled.
B. 3 PART TEXTURE
a. 5th is omitted. Final I chord may consist of a tripled root.
b. Incomplete triads have root doubled.
c. Never double leading tone 7.
4TH/5TH ROOT PART WRITING RULES:
A. 4 PART TEXTURE
a. Common Tone and Stepwise
1. Keep in the same voice the tone that is common to both chords.
2. 2 upper parts move by step in same direction.
3. Stepwise is ascending for P5 down.
4. Stepwise is descending for P5 root moving up.
b. Similar Motion by 2nd or 3rd
1. Move all 3 upper parts in same direction.
2. No leap larger than a 3rd.
3. Motion will be descending for P5 root movement down (P4 up.)
4. Motion will be ascending for P5 root movement up (P4 down.)
5. 7 can leap down to 5 in an inner voice.
c. Tertian Leap – Common Tone – Stepwise
1. Use to change between close and open structures.
2. Keep in same voice tone that is common to both chords.
3. Voice that has 3rd in first chord leaps to provide 3rd in second chord.
4. Remaining voices move by step.
5. 7 can move to 3 if in an inner voice.
B. 3 PART TEXTURE
a. Each chord MUST contain a root and a 3rd.
b. Aim for smooth voice leading over complete chords.
3RD/6TH ROOT PART WRITING RULES:
A. 4 PART TEXTURE
a. Two Common Tones and Stepwise
1. Doubled root, one upper voice moves.
2. 2 upper voices that have tones in common with the second chord remain stationary.
3. Remaining voices move by step.
4. Stepwise motion upward for roots descending 3rd (6th up.) apart.
5. Stepwise motion downward for ascending 3rd (6th up.)
B. 3 PART TEXTURE
a. Watch ascending root movement.
b. Do not omit 5th of second chord.
REMEMBER: 2 TRIADS WILL ALWAYS HAVE 2 PITCH CLASSES IN COMMON.
2ND/7TH ROOT PART WRITING RULES:
A. 4 PART TEXTURE
a. Contrary to the Bass
1. If root is doubled in first chord, bass moves up by step.
2. Upper voices move down to nearest chord tone.
3. Bass moves down, upper voices move up.
4. Deceptive Progression:
- 7 moves parallel with bass resolving up to 1.
- Other 2 voices move down to chord tones.
- Results in doubled 3rd in vi (VI) chord.
- OK for 7 to move to 6 in inner voice in major mode ONLY.
B. 3 PART TEXTURE
a. Complete Triad followed by a triad with 2 roots and a 3rd
b. OR the opposite.
c. 7 goes to 1 (except in inner voice in Major Mode.)
1. Same roots (repeated chords)
2. 4th Apart (5th)
3. 3rd Apart (6th)
4. 2nd Apart (7th)
REPEATED ROOT RULES:
A. 4 PART TEXTURE
a. All members of triad usually present.
b. Root is doubled. Leading tone 7 should NOT be doubled.
B. 3 PART TEXTURE
a. 5th is omitted. Final I chord may consist of a tripled root.
b. Incomplete triads have root doubled.
c. Never double leading tone 7.
4TH/5TH ROOT PART WRITING RULES:
A. 4 PART TEXTURE
a. Common Tone and Stepwise
1. Keep in the same voice the tone that is common to both chords.
2. 2 upper parts move by step in same direction.
3. Stepwise is ascending for P5 down.
4. Stepwise is descending for P5 root moving up.
b. Similar Motion by 2nd or 3rd
1. Move all 3 upper parts in same direction.
2. No leap larger than a 3rd.
3. Motion will be descending for P5 root movement down (P4 up.)
4. Motion will be ascending for P5 root movement up (P4 down.)
5. 7 can leap down to 5 in an inner voice.
c. Tertian Leap – Common Tone – Stepwise
1. Use to change between close and open structures.
2. Keep in same voice tone that is common to both chords.
3. Voice that has 3rd in first chord leaps to provide 3rd in second chord.
4. Remaining voices move by step.
5. 7 can move to 3 if in an inner voice.
B. 3 PART TEXTURE
a. Each chord MUST contain a root and a 3rd.
b. Aim for smooth voice leading over complete chords.
3RD/6TH ROOT PART WRITING RULES:
A. 4 PART TEXTURE
a. Two Common Tones and Stepwise
1. Doubled root, one upper voice moves.
2. 2 upper voices that have tones in common with the second chord remain stationary.
3. Remaining voices move by step.
4. Stepwise motion upward for roots descending 3rd (6th up.) apart.
5. Stepwise motion downward for ascending 3rd (6th up.)
B. 3 PART TEXTURE
a. Watch ascending root movement.
b. Do not omit 5th of second chord.
REMEMBER: 2 TRIADS WILL ALWAYS HAVE 2 PITCH CLASSES IN COMMON.
2ND/7TH ROOT PART WRITING RULES:
A. 4 PART TEXTURE
a. Contrary to the Bass
1. If root is doubled in first chord, bass moves up by step.
2. Upper voices move down to nearest chord tone.
3. Bass moves down, upper voices move up.
4. Deceptive Progression:
- 7 moves parallel with bass resolving up to 1.
- Other 2 voices move down to chord tones.
- Results in doubled 3rd in vi (VI) chord.
- OK for 7 to move to 6 in inner voice in major mode ONLY.
B. 3 PART TEXTURE
a. Complete Triad followed by a triad with 2 roots and a 3rd
b. OR the opposite.
c. 7 goes to 1 (except in inner voice in Major Mode.)
