Chapter 7: Sequences and Circle of 5ths
Sequence: a pattern that is repeated immediately in the same voice but in a different pitch class.
Tonal Sequence: Keeps the pattern in a single key. Modifiers (sharps, flats) of intervals will change.
Real Sequence: Transposes pattern to new key.
Modified Sequence: Repetitions of pattern are neither tonal nor real (ie: altering intervals.)
Real Imitation: Exact transposition of melody. Pattern repetition occurs in different voice.
Circle of 5ths Progression: Series of roots related by descending 5ths. (Eventually a °5 will appear.) Keep moving backwards to create chord progression.
THE I – V CHORDS:
1. Most important progression.
2. Not all dominant chords have same significance.
3. Tonic can be prolonged through use of weak dominant chords in inversion.
THE ii CHORD:
1. Functions as a pre-dominant chord: ii – V.
THE iii CHORD:
1. When 3rd is found in a major mode Bass line, the chord above it is almost always a I6 rather than a iii.
2. When it follows the natural descending 5ths progression, it will go to a vi.
3. III in minor is used more frequently.
4. Useful in harmonizing a 1–7–6 Soprano line.
THE vii° CHORD:
1. Usually acts as a substitute for V.
2. So similar to V that moving from one to another is not considered a progression.
3. Customary goal is not iii (or III) but the I.
4. If used with V, V will come 2nd.
5. Common use is between I and I6 or I6 and I. This may involve a voice exchange between Bass and an upper voice: One goes 1–2–3, the other will go 3–2–1.
6. vii°6 is useful in harmonizing a 6–7–1 Soprano line.
THE IV CHORD:
1. Has a pre-dominant function.
2. Moves directly to V or vii°.
3. OR expands pre-dominant sound by going to ii or ii6.
4. Plagal progression: IV – I.
COMMON EXCEPTIONS:
1. V-vi (deceptive progression): when vi substitutes for I it can be followed by any chord.
MINOR MODE DIFFERENCES:
A. Most chord functions is the same for major and minor.
B. The mediant triad is a common feature in minor.
a. It represents the relative major key.
C. Variability of 6th and 7th will occasionally produce chords of different quality and function.
a. The subtonic VII, sounding like the V in the key of the relative major i.e.: V of III.
b. The minor v (usually v6) after which the descending 7th moves to 6th as part of a iv6 chord.
c. The minor v does not have a dominant function.
d. Also v6 – iv6, v6 functions as a passing chord that connects tonic to pre-dominant iv6.
MORE ON HARMONIC SEQUENCES:
1. The sequential pattern may result in unusual doublings, root position diminished chords, and unusual leaps. That is ok.
2. Chords may not function in a sequence in their usual way.
3. Inversions do not affect a harmonic sequence.
4. Sequences my begin and end at any point in the pattern.
Tonal Sequence: Keeps the pattern in a single key. Modifiers (sharps, flats) of intervals will change.
Real Sequence: Transposes pattern to new key.
Modified Sequence: Repetitions of pattern are neither tonal nor real (ie: altering intervals.)
Real Imitation: Exact transposition of melody. Pattern repetition occurs in different voice.
Circle of 5ths Progression: Series of roots related by descending 5ths. (Eventually a °5 will appear.) Keep moving backwards to create chord progression.
THE I – V CHORDS:
1. Most important progression.
2. Not all dominant chords have same significance.
3. Tonic can be prolonged through use of weak dominant chords in inversion.
THE ii CHORD:
1. Functions as a pre-dominant chord: ii – V.
THE iii CHORD:
1. When 3rd is found in a major mode Bass line, the chord above it is almost always a I6 rather than a iii.
2. When it follows the natural descending 5ths progression, it will go to a vi.
3. III in minor is used more frequently.
4. Useful in harmonizing a 1–7–6 Soprano line.
THE vii° CHORD:
1. Usually acts as a substitute for V.
2. So similar to V that moving from one to another is not considered a progression.
3. Customary goal is not iii (or III) but the I.
4. If used with V, V will come 2nd.
5. Common use is between I and I6 or I6 and I. This may involve a voice exchange between Bass and an upper voice: One goes 1–2–3, the other will go 3–2–1.
6. vii°6 is useful in harmonizing a 6–7–1 Soprano line.
THE IV CHORD:
1. Has a pre-dominant function.
2. Moves directly to V or vii°.
3. OR expands pre-dominant sound by going to ii or ii6.
4. Plagal progression: IV – I.
COMMON EXCEPTIONS:
1. V-vi (deceptive progression): when vi substitutes for I it can be followed by any chord.
MINOR MODE DIFFERENCES:
A. Most chord functions is the same for major and minor.
B. The mediant triad is a common feature in minor.
a. It represents the relative major key.
C. Variability of 6th and 7th will occasionally produce chords of different quality and function.
a. The subtonic VII, sounding like the V in the key of the relative major i.e.: V of III.
b. The minor v (usually v6) after which the descending 7th moves to 6th as part of a iv6 chord.
c. The minor v does not have a dominant function.
d. Also v6 – iv6, v6 functions as a passing chord that connects tonic to pre-dominant iv6.
MORE ON HARMONIC SEQUENCES:
1. The sequential pattern may result in unusual doublings, root position diminished chords, and unusual leaps. That is ok.
2. Chords may not function in a sequence in their usual way.
3. Inversions do not affect a harmonic sequence.
4. Sequences my begin and end at any point in the pattern.