Natural chord tensions form corresponding arpeggios on top of chords.
- A minor 7th has three tensions: 9, 11, 13. Together with the 7th they form a major 7 arpeggio a tone below.
This relationship results in the following table:
|chord||From 7th||From 9th|
|Minor 7th||7b+9+11+13 = Maj7||9+11+13+R = Min 7th|
|Min 7th b5||7b+9+11+b13 = Full diminished||9+11+b13+R = Min 7th b5|
|Dom 7th||7b+9+#11+13 = 5# 7th||9+11#+13+R = Dom 7th|
|Maj 7th||7+9+#11+13 = Min 7th||9+11#+13+R = Dom 7th|
* (R = Root, 8va)
Patterns start to emerge, as some tensions produce the same kind of chords (but a tone away).
Extremely fun stuff.
As for altered tensions in dominant 7ths, the possibilities explode:
|Dom 7th tensions||From 7th||From 9th|
|#9 #11||7+#9+#11 = 2nd inv Min/sus4?||#9+#11(+b13!)+R = Full diminished|
Once you get ahold of these possibilitys, you realize you can play chord superimpositions that emphatize tensions. A good practice routine should build up the memory of these relationships between chord types and what kind of upper structure harmonic structures one can create.
So let’s do that, and take a systematic approach to this information, by chord quality:
Minor 7th chords
How many upper structure arpeggios can we build from minor 7th chords and tensions?
|Interval||Tensions and chord tones||Resulting chord|
|9||9+11+13b+R||Min 7 (5b)|
|13||13+3+3rd||Min 7 (5b)|
The result is quite pedestrian: you build… the chords of the majord scale (gasp!), with a bit of wiggle room in those spots where you can treat the minor base chord as dorian or phrygian (meaning, considering the 13 or the b13 tension). Note that I’ve not included 9b, even if it’s in there in the phrygian mode, since it’s usually considered pretty disonant over minor 7ths.
Some interesting notes here and there:
- Three minor chords inside the minor chord (from the 9, 11th and 5th).
- You can briefly imply another tonality by clever tension use. My guess is that most options with 13b will imply a tonic funcion, and in that case, a minor 6 or Minor/major chord would work much better, so one should refer to those. Else, you could substitute by another tonic (Maj7/Maj6 a minor third away, a Minor/Major a fourth away), but then it would be a substitution, not an chord superimposition.