See also post 203 and 321, 322.
This is harmonic improvisation and parallel melodic improvisation much like the jazz Blues that are using 3 only chords I IV V, or improvisations as in Irish reels with 2 only chords or improvisations as in Cretan condillies with 2 only chords. Also some folk songs of the Cape Verde with only 2 chords.
Here we have similarly the general rule of a scale of chords of 2 only chords . There 3 types of such pairs of chords HARMONIC PAIR (roots an interval of 5th or 4th away) , MELODIC PAIR (roots an interval of 3rd away) CHROMATIC PAIR (roots an interval of 2nd away) . E.G. I it is X7 Y where the one is a 7nth chord and the second has a root which is an interval of 4th away from the root of the first chord it is an harmonic pair. .In other words the two chords are in the harmonic relation (see post 30 ) are successive in the wheel of 4ths. The reason for this is so as to have in the subconscious
a simple pattern in harmony (although with random variations from random sequences of these 2 chords)
Also another important reason is that
the 2 chords define usually at least one diatonic or other scale which simplifies the melodic improvisation.
In a diatonic scale some choices for such a pair of chords could be
V7 I (5M7 1M) HARMONIC PAIR
I7 IV (1M7 4M) HARMONIC PAIR
vii iii (7dim 3m) HARMONIC PAIR
iii7 vi (3m7 6m) HARMONIC PAIR
vi7 ii (6m7 2m) HARMONIC PAIR
ii7 V (2m7 5M) HARMONIC PAIR.
About the symbols: In a C major scale the symbols denote the next chords
I=1M=C
ii=2m=Dm
iii=3m=Em
IV=4M=F
V=5M=G
vi=6m=Am
vii=7d=Bdim
Such triads of harmonic pairs may be already in the 3 main relations Harmonic relation , Melodic relation and chromatic relation defined from the interval of the roots of the first chord of each pair.
E.g. the triad of harmonic pairs vii iii (7dim 3m) , (3M7 6m), (6m7 2m) are in harmonic-harmonic-harmonic relations . While the triad of harmonic pairs
(6m7 2m) , (3M7 6m), (5M7 1M) are in harmonic-melodic-chromatic relation.
All 6 combinations (the inverses not included) of such triads of harmonic pairs on the first pair are
HARMONIC-HARMONIC
HARMONIC-MELODIC
MELODIC-MELODIC
HARMONIC-CHROMATIC
CHROMATIC-CHROMATIC
CHROMATIC-MELODIC
ETC
By fixing particular pattern of permutations and repetitions of these 2 chords (as in variations of the rhythm and chord progressions in 12-bars blues) e.g.
X7 X7 X7 X7
Y Y X7 X7
X7 X7 Y Y
etc
we have the backtrack of an easy harmony to define with melodic improvisations.
The improvisation is spending most of the time between the elements of each harmonic pair by oscillating or alternating them and then after repetition is sufficient it moves to another harmonic pair staying again there sufficient ime. This is very common in early New Orleans Jazz songs.
Also the
simplicial submelody of such improvisations will be fixed following the chord progression pattern.
The chromatic pairs of chords in the diatonic scale may get the the names ofthe modes of the scale too
1M-2m=IONIAN
2m-3m=DORIAN
3m-4M=FRYGIAN
4M-5M=LYDIAN
5M-6m=MYXOLYDIAN
6m-7d=AEOLIAN
7d-1M=LOCRIAN
(see also post 364 , 225 and 325 )
It is important also to realize that these 7 pairs of chords in chromatic relation define not only tetrachords but also hexatonic scales (and corresponding harmonicas) as in the post 291.
From the triplets of chords that correspond to modes as below
1. IONIAN : HARMONIC TRIPLET (1M, 4M, 5M)
2. DORIAN : HARMONIC TRIPLET (2m, 5M, 6m)
3. PHRYGIAN : HARMONIC TRIPLET (3m, 6m, 7d)
4. LYDIAN: HARMONIC TRIPLET (4M, 7d,1M)
5. MIXOLYDIAN: HARMONIC TRIPLET (5M, 1M,2m)
6. AEOLIAN: HARMONIC TRIPLET (6m, 2m, 3m)
7. LOCRIAN: HARMONIC TRIPLET (7d, 3m, 4M)
If we re-harmonize the above triplets to include the lue notes 5# for the harmonic minor and 23, 5# for the double harmonic minor we get a latin jazz style of them as follows
1. IONIAN : HARMONIC TRIPLET (1M, 4M, 5M)
2. DORIAN : HARMONIC TRIPLET (2m, 5M, 6m) or in Hminor 6M7, 2m , 5m)
3. PHRYGIAN : HARMONIC TRIPLET (3m, 6m, 7M7)
4. LYDIAN: HARMONIC TRIPLET (4M, 7d,1M)
5. MIXOLYDIAN: HARMONIC TRIPLET (5M, 1M,2m)
6. AEOLIAN: HARMONIC TRIPLET (6m, 2m, 3m) or in Hminor 3M7, 6m,2m
7. LOCRIAN: HARMONIC TRIPLET (7d, 3m, 4M)
In the next we may compose songs with first part (couple) a sad triplet or pair signifying a mode and resolving to the refrain to a happy triplet or pair (usually the Ionian or Mixolydian)
Here are examples of chord progressions of such songs
E. g. Aeolian-> Ionian
2m, 3M7
6m, 2m
Resolving to
1M 4M
5M7 1M
Frygian-> Ionian
3m 6m
7M7 3m
Resolving to
Dorian-> Ionian
We may extract pairs of chords that define modes as folows
1. IONIAN : HARMONIC pair (5M, 1M)
2. DORIAN : HARMONIC PAIR ( 6m, 2m)
3. PHRYGIAN : HARMONIC PAIR (7d, 3m)
4. LYDIAN: HARMONIC PAIR (1M 4M)
5. MIXOLYDIAN: HARMONIC PAIR (2m, 5M)
6. AEOLIAN: HARMONIC PAIR (3m 6m)
7. LOCRIAN: pseudo HARMONIC PAIR (4M 7d)
Arpeggios of such a pair ofchords in chrmatic relation is often performed on the guitar by what is called sweep picking
We cannot stress much the importance of triads of chords (but also of notes intervals and scales) in improvisation.
A good application is to realize that as a diatonic scale is characterized as chords on the wheel by 4ths by its 3 chords on the steps 1M, 4M , 5M (harmonic triplet of chords) , OR 7d 1M 2m (chromatic tripler of chords) the same can apply for the modes of the diatonic scale.
Besides the basic harmonic triplets (in other words a sequence of 3 chords X1,X2,X3 so that X1-X2 , X2-X3 are harmonic relations od chords, in other words chords that their roots differ by an interval of 4th (5th)) , there are also the chromatic triplets (in other words a sequence of 3 chords X1,X2,X3 so that X1-X2 , X2-X3 are chromatic relations od chords, in other words chords that their roots differ by an interval of 2nd). BOTH ARE BASIC TYPES OF TRIPLETS. In other words with the 3 CHORDS OF THE TRIPLET WE CAN ACCOMPANY ANY MELODY IN THE DIATONIC SCALE. WE CANNOT HAVE THIS PROPERTY OF BEING HARMONICALLY A BASE OF 3 CHORDS FOR MELODIC TRIPLETs (in other words a sequence of 3 chords X1,X2,X3 so that X1-X2 , X2-X3 are melodic relations of chords, in other words chords that their roots differ by an interval of 3rd)
The chords of a mode of a diatonic scale at the steps 1,4,5 (or 7,1, 2) of it characterize its mood.
For example for the mixolydian mode of the diatonic scale from C ,(G, A, B , C, D, E, F, G) the chords at the steps 1,4 ,5 are the G, C, Dm) thus the 1, 2, 5 or I, ii, V of the original ionian and are the base of blues jazz.
Based on this perception, the 7 modes of the diatonic scale have the following chord triads:
(that is chords on their 1st 4th and 5th step, and we symbolize by m=minor M=major d=diminsihed.
1. IONIAN : CHROMATIC TRIPLET (7d, 1M, 2m)
2. DORIAN : CHROMATIC TRIPLET (1M, 2m, 3m )
3. PHRYGIAN : CHROMATIC TRIPLET(2m,3m, 4M)
4. LYDIAN: CHROMATIC TRIPLET(3m, 4M, 5M)
5. MIXOLYDIAN: CHROMATIC TRIPLET (4M, 5M, 6m)
6. AEOLIAN: CHROMATIC TRIPLET (5M, 6m, 7d)
7. LOCRIAN: CHROMATIC TRIPLET (6m, 7d, 1M)
We may compare the basic chromatic triplets with the basic harmonic triplets (see also post 222)
1. IONIAN : HARMONIC TRIPLET (1M, 4M, 5M)
2. DORIAN : HARMONIC TRIPLET (2m, 5M, 6m)
3. PHRYGIAN : HARMONIC TRIPLET (3m, 6m, 7d)
4. LYDIAN: HARMONIC TRIPLET (4M, 7d,1M)
5. MIXOLYDIAN: HARMONIC TRIPLET (5M, 1M,2m)
6. AEOLIAN: HARMONIC TRIPLET (6m, 2m, 3m)
7. LOCRIAN: HARMONIC TRIPLET (7d, 3m, 4M)
Besides these 2 types of basic triplets we have also a 3rd type X1 X2 X3 , where X1-X2 is a chromatic relation and the X2-X3 is an harmonic relation or vice versa. We may call them the mixed
basic chromatic-harmonic triplets. E.g. the basic triplet that is used sometimes in blues 1M 2m, 5M , is such as 1M-2m have chromatic relation while 1M-5M harmonic relation.
To convert a basic harmonic triplet to another chromatic or mixed basi triplet we utilize correspondences where we correspond each of the 3 main major chords of the diatonic scale with their lower minor relative and the 5M7 with the 7d. Therefore
2m<->4M
3m<->5M
6m<->1M
7d<-> 5M7
The same arguments may apply for the chromatic tonality where some of the mnor chords become major and some of the major chords minor. E.g. We have the harmonic triplet (3M7, 6m ,2m ) of the frygian mode and the harmonic triplet (7M7-3M7-6m) of the Locrian mode which are combined with the more standard harmonic triplets of the diatonic tonality of the dorian mode (2m-5M7-1M) or the myxolydian mode (5M7-1M7-4M) .
For alternative basic chromatic triplets of the chromatic tonality (that corresponds to the harmonic minor and double harmonic minor) we have the triplets (we notice that thsi type of chromatic tonality gives for the basic chromatic triplets, cases of 2 major chords and one minor, thus the major chords are dominating!)
IONIAN MODE: 7M-1M-2m
DORIAN MODE: 1M-2m-3M
FRYGIAN MODE: 2m-3M7-4M
LYDIAN MODE: 3M-4M-5M
AEOLIAN MODE: 5M-6m-7M
LOCRIAN MODE: 6m-7M-1M