8.10 Augmented sixth chords - seventh chords
| Category: Harmony | Tags: Chords, Seventh chords |
Theory
In Chapter 8.8 Augmented sixth chords - triads you’ve learned what double-diminished flat-fifth and major flat-fifth triads are. In this chapter, you will learn that there are two kinds of seventh chords, namely the double-diminished seventh chord and the dominant seventh chord with flat fifth. Double-diminished seventh chord and dominant seventh chord with flat fifth are altered chords. These chords do not come naturally in a major or minor scale, but are created by alteration of tones. In the examples I show how to make double-diminished seventh chords and dominant seventh chords with flat fifth. You are goning to make them yourself in the exercises.
1. What is a double-diminished seventh chord?
Double-diminished seventh chord is derived from alteration of the fourth degree (IV7). This results in a seventh chord with a diminished third, a diminished fifth and a diminished seventh. This seventh chord is called a double-diminished seventh chord.
Double-diminished seventh chord in the major scale
In the major scale, a double-diminished seventh chord is made by raising the root and lowering the third and seventh.
Examples
How to make a double-diminished seventh chord in C major?
Double-diminished seventh chord in the minor scale
In the minor scale, a double-diminished seventh chord is made by raising the root (the third and seventh are already lowered).
Examples
How to make a double-diminished seventh chord in C minor?
Examples
Which tones do you get if you make double-diminished seventh chords on the natural notes?
2. The German sixth chord
Double-diminished seventh chord only occurs in first inversion. The lowest tone is the lowered third, the highest tone is the raised root. The distance between these two tones is an augmented sixth. The first inversion of a double-diminished seventh chord is called a German sixth chord (Ger6)
German sixth chord in the major scale
In C major, the fourth degree (IV7) is comprised of the tones F - A - C - E. By raising the root and lowering the third and seventh we get F# - Ab - C - Eb, this is a double-diminished seventh chord. The first inversion is Ab - C - Eb - F#, this is a German sixth chord.
Examples
How to make a German sixth chord in the C major scale?
German sixth chord in the minor scale
In C minor, the fourth degree (IV7) is comprised of the tones F - Ab - C - Eb. By raising the root we get F# - Ab - C - Eb, this is a double-diminished seventh chord. The first inversion is Ab - C - Eb - F#, this is a German sixth chord.
Examples
How to make a German sixth chord in the C minor scale?
3. What is a dominant seventh chord with flat fifth?
Dominant seventh chord with flat fifth is derived from alteration of the second degree (II7). This results in a seventh chord with a major third, a diminished fifth and a minor seventh. This triad is called a dominant seventh chord with flat fifth.
Dominant seventh chord with flat fifth in the major scale
In the major scale, a dominant seventh chord with flat fifth is made by raising the third and lowering the fifth.
Examples
How to make a dominant seventh chord with flat fifth in C major?
Dominant seventh chord with flat fifth in the minor scale
In the minor scale, a dominant seventh chord with flat fifth is made by raising the third (the fifth is already lowered).
Examples
How to make a dominant seventh chord with flat fifth in C minor?
Examples
Which tones do you get if you make dominant seventh chords with flat fifth on the natural notes?
4. The French sixth chord
Dominant seventh chord with flat fifth only occurs in second inversion. The lowest tone is the lowered fifth, the highest tone is the raised third. The distance between these two tones is an augmented sixth. The second inversion of a dominant seventh chord with flat fifth is called a French sixth chord (Fr6).
French sixth chord in the major scale
In C major, the second degree (II7) is comprised of the tones D - F - A - C. By raising the third and lowering the fifth we get D - F# - Ab - C, this is a dominant seventh chord with flat fifth. The second inversion is Ab - C - D - F#, this is a French sixth chord.
Examples
How to make a French sixth chord in C major?
French sixth chord in the minor scale
In C minor, the second degree (II7) is comprised of the tones D - F - Ab - C. By raising the third we get D - F# - Ab - C, this is a dominant seventh chord with flat fifth. The second inversion is Ab - C - D - F#, this is a French sixth chord.
Examples
How to make a French sixth chord in C minor?
5. German sixth chord and French sixth chord in practice
In fact, German sixth chord and French sixth chord are built on the lowered sixth degree. The highest tone of these chords is the raised fourth tone. Both tones are resolving to the dominant, the fifth degree.
German sixth chord and French sixth chord are always resolving to the dominant, the fifth degree: Ger6 - V7 or Fr6 - V7.
6. Practise
Double-diminished seventh chord and dominant seventh chord with flat fifth
Harmony exercise 8l: practise determining the third and fifth of a double-diminished seventh chord and dominant seventh chord with flat fifth.
Harmony exercise 8m: practise making double-diminished seventh chord and dominant seventh chord with flat fifth on the natural notes.
Harmony exercise 8n: practise making double-diminished seventh chord and dominant seventh chord with flat fifth on all notes.
German sixth chord and French sixth chord
Harmony exercise 8o: practise making German sixth chord and French sixth chord with given root on the natural notes.
Harmony exercise 8p: practise making German sixth chord and French sixth chord with given root on all notes.
Harmony exercise 8q: practise making German sixth chord and French sixth chord on the natural notes.
Harmony exercise 8r: practise making German sixth chord and French sixth chord on all notes.
Get the full courseSummary
Double-diminished seventh chord and dominant seventh chord with flat fifth
Double-diminished seventh chord is derived from alteration of the fourth degree (IV7):
- In the major scale: by raising the root and lowering the third and seventh.
- In the minor scale: by raising the root.
- This results in a seventh chord with a diminished third, a diminished fifth and a diminished seventh.
- The first inversion of a double-diminished seventh chord is called a German sixth chord (Ger6).
Dominant seventh chord with flat fifth is derived from alteration of the second degree (II7):
- In the major scale: by raising the third and lowering the fifth.
- In the minor scale: by raising the third.
- This results in a seventh chord with a major third, a diminished fifth and a minor seventh.
- The second inversion of a dominant seventh chord with flat fifth is called a French sixth chord (Fr6).
Double-diminished seventh chord and dominant seventh chord with flat fifth on the natural notes |
||
| natural note | double-diminished seventh chord | dominant seventh chord with flat fifth |
| A | A Cb Eb Gb | A C# Eb G |
| B | B Db F Ab | B D# F A |
| C | C Ebb Gb Bbb | C E Gb Bb |
| D | D Fb Ab Cb | D F# Ab C |
| E | E Gb Bb Db | E G# Bb D |
| F | F Abb Cb Ebb | F A Cb E |
| G | G Bbb Db Fb | G B Db F |
Practise
Double-diminished seventh chord and dominant seventh chord with flat fifth
Harmony exercise 8l: practise determining the third and fifth of a double-diminished seventh chord and dominant seventh chord with flat fifth.
Harmony exercise 8m: practise making double-diminished seventh chord and dominant seventh chord with flat fifth on the natural notes.
Harmony exercise 8n: practise making double-diminished seventh chord and dominant seventh chord with flat fifth on all notes.
German sixth chord and French sixth chord
Harmony exercise 8o: practise making German sixth chord and French sixth chord with given root on the natural notes.
Harmony exercise 8p: practise making German sixth chord and French sixth chord with given root on all notes.
Harmony exercise 8q: practise making German sixth chord and French sixth chord on the natural notes.
Harmony exercise 8r: practise making German sixth chord and French sixth chord on all notes.
Get the full course