Over the V7(b9) Chord (G7)
As we have seen previously the basic scale to play over a dominant 7th chord in minor harmonic key is the Phrygian dominant mode.
By taking the first, the third, the fifth and the minor seventh we obtain a dominant 7th arpeggio.
Playing this scale and arpeggio is a little too ordinary and not very interesting. In this case we usually play a diminished seventh arpeggio starting on the major third (3) of the chord.
Diminished seventh arpeggio (3 to b9)
| Bdim7 Arpeggio |
B |
D |
F |
Ab |
| Formula |
1 |
b3 |
b5 |
bb7 |
Here is a comparison between the G Phrygian mode and the Bdim7 arpeggio.
- B is the major third of G7
- D is the fifth
- F is the minor seventh
- Ab is the flat ninth
| G Phrygian Dominant |
G |
Ab |
B |
C |
D |
Eb |
F |
| Bdim7 arpeggio |
X |
b2 (b9) |
3 |
X |
5 |
X |
b7 |
​
Playing a diminished seventh arpeggio over a dominant seventh chord brings the b9.
This technique also called "3 to b9" is widely used by Wes Montgomery, Grant Green and many jazz players.
Altered scale
To enlarge your musical vocabulary it is possible to think G7 as an altered chord, therefore using notes of the altered scale over it.
The "Altered scale" (also called "super Locrian mode") is the seventh mode of the melodic minor scale.
Playing it over a dominant 7th chord brings tension and more sophisticated sound.
The combination of the Locrian # 2 mode and the altered scale works well over II-V sequences.
| G Altered Scale |
G |
Ab |
Bb |
B |
Db |
Eb |
F |
| Formula |
1 |
b9 |
#9 |
3 |
b5 (#11) |
#5 (b13) |
b7 |
| Intervals |
H |
W |
H |
W |
W |
W |
W |