37. LIQUID 4-STRINGS HARMONY OR LIQUID-CHORD AND MELODY IMPROVISATION THROUGH SCALES OF CHORDS

We must remind here the fundamental philosophy of musical composition and improvisation.

Musical improvisation is not a technical skill that one “learns to do.” It is a natural spontaneous process that occurs first in the imagination. It is often a natural language of the soul, as we have the language of words. But that is why it is understood by people that do not even speak the same language of words

The main goal of musical composition and improvisation is not the output musical piece, but the EXISTENTIAL FUNCTION of the process of creating and listening to the musical piece. 

Here is an example of mediative improvisation by Estas Tonne

https://www.youtube.com/watch?v=7gphiFVVtUI

WHAT IS IMPORTANT TO UNDERSTAND IN ALL OF THE MUSICAL PRACTICE IS THAT WE ARE TO CONCENTRATE NOT SO MUCH ON THE ACTION OF THE FINGERS OR THE MENTAL IDENTITY OF THE MUSIC AS ON THE FEELING OF THE SOUND. NEVERTHELESS, ALL THE THREE COMPONENTS SHOULD BE AVAILABLE: THE MENTAL IDENTITY OF THE MUSIC, THE FEELING OF THE SOUND AND THE  ACTION OF THE FINGERS.
THE BLOG, AMONG OTHER GOALS, IS DEDICATED ALSO IN TO CREATING SIMPLER MENTAL IMAGES OF THE MUSIC, WHILE PLAYING AND IMPROVISING, SO THAT THE ACTION OF THE HANDS AND FINGERS FLOWS WITHOUT DIFFICULTY


IN MY APPROACH IN THIS BOOK I FAVOR MIXTURE OF AN IN ADVANCED COMPOSED MUSIC PIECE AND  A LATER IMPROVISATION OVER IT RATHER THAN A 100% PRIMA-VISTA IMPROVISATION. THE REASON IS OBVIOUS. THERE ARE ADVANTAGES OF MUSICAL COMPOSITION THAT WILL TAKE MORE TIME THAN THE DURATION OF THE MUSICAL PIECE OVER A DIRECT IMPROVISATIONAL CREATION OF IT AS WE LISTEN TO IT. THE FORMER GIVES US THE OPPORTUNITY OF A BETTER QUALITY MUSICAL CREATION AND A BETTER BALANCE OF THE PREVIOUS TRIANGLE OF MUSICAL MENTAL IMAGES, SOUND FEELINGS AND FINGER ACTIONS.

LIQUID 4-STRING HARMONY OR LIQUID-CHORD AND MELODY IMPROVISATION:

The current approach is essentially the approach of a chord progression, with chords of 4 notes, and simple melodic improvisation within the chord where ALL THE NOTES OF THE MELODY ARE NOTES OF THE UNDERLYING CHORDS. 

The DAE system (see post 3) suggest already a way to play simultaneously chords and melody with the same instrument

By restricting the playing of the guitar on the 4 higher strings,or playing corresponding isosmorphically tuned to these 4-strings of the guitar instruments (like ukulele, Greek buzuki, etc) I discovered the remarkably simple DAE system, which handles all the major and minor chords as having only one of the 3-shapes of D (like open D major) A (like open A major) and E (like open E major). 

Approximately the 3 shapes have the next distribution on the fretboard

D4

E4

F4

G4

A4

B4

C5

D5

A3

B3

C4

D4

E4

F4

G4

A4

E3

F3

G3

A3

B3

C4

D4

E4

This distribution of the chord suggest also a way to play simultaneously melodies with chords: We play the melody on the strings D,G,B,E (higher 4)  and then at each note we try the roots maximal chordification (each note of the melody as root of a chord minor or major or dim7 or augmented  according to what that fits  in the scale), and then we simplify the chordification to less chords with rules that successive chords in resolution relation are better than in relative relation which in its turn is better than the complementary relation, so as to result in to a stable simple harmonic background. It is always also better to use chords on the fretboard that contain the note of the melody in the exact octave it is. So this defines that we do not play only open chords but chords distributed on the fretboard as in the above table.


GENERAL RULE FOR GOOD CHORD PROGRESSIONS OF IMPROVISATION AND COMPOSITION

Chord progressions that two successive chords  are always either 
1) an interval of  4th , that is successive n the wheel of 4ths 
2) Relative chords where major turns to minor and vice-versa, thus roots-distance  an interval of 3rd 3) Chromatic relation , in other words the roots differ by a semitone 

are best chord progressions for parallel translations of melodic themes by intervals of octave, 4th-5th, 3rd and semitone. 

Example  

C-> Am->Dm_->G->C->F->Dm->Dm7->G7->C etc

ARPEGGIOS AND DEA SYSTEM OF 4-STRING INSTRUMENTS (SEE POST 67) FOR SUCH CHORD PROGRESSIONS:

For the 4-string (double or simple strings) instruments of post 67, that are most of the ethnic music instruments , the chord shapes theory simplifies to the DEA instead of the CAGE of the 6-string guitar. Similarly the arpeggios of the chords, although are not identical with the shapes of the chords in a 6-string guitar, for the above 4-string instruments , they are identical with the chord shape! Thus knowing the chords means knowing their arpeggios of them too, which gives immediately a way of easy improvisation along a chord progression! The randomness is double a) in the choice of the chord progressions as above , in particular the chord transitions as described b) in the choice of the way to play soloing inside the arpeggio of such chords in particular the melodic themes 4 transformations.This  is easiest done with the 4-string instruments of the ethnic music (see post 67) . Such arpeggios can be extended to contain the 6th and 7th thus being arpeggios of the chord as with 6th  or 7nth (Notice that 6th are identical with minor 7ths X6=Ym7 and Xm6=Ym7b5, where X and Y are a minor 3rd apart as in relative chords). Some times extended so as to contain the chord with 2nd or 4th too. The transformations of the melodic themes, (see post 76) and in particular the 4 basic translations, inversions, rhythm variations and melodic density expansion or contraction can be conducted with a mini 4-or-5-notes-scale when a chord is playing which its arpeggio or extended 6th or 7th  arpeggio! In this way the melody always remains in accordance with the underlying chord and chord progression. Thus arbitrary such 3-types of chord transitions as above and arbitrary such 4 transformations of melodic themes will result in to a rich , free but well harmonic and melodic improvisation and composition! 

  

Here is a video where the soloing around any chord X is the pentatonic scale of its root, which equivalent with the arpeggio of the chord X with 6th and added 9th (or 2nd) thus X6add9.

https://www.youtube.com/watch?v=MVSzSVYqjbU&t=44s

Usually, the improvisation in Jazz, is melody-oriented in the sense, that it usually has a predetermined chord progression and based on that many melodies are improvised. We described in detail the composition and improvisation method that starts with the chord progression at first and then composes the melody in post 9. 

We will develop here a second level of the improvisation where we improvise at first on the chord progression and parallel to it, based on the melodic centers we improvise on melodies. The melodic centers (simplicial sub-melody)  are not too much more complicated than the chord progression.

For this end, we describe again the 3 wheels of chords, the chromatic, the one by intervals of 3rds and the one by intervals of 4ths, and 3 types of chord cycles from them, the short (3-chords), the middle (6-7 chords) and the full cycle (12-15 chords). In the wheel by 3rds there are 2 medium size sub-cycles (See below)    These subcycles of chords, for the chord progressions improvisation, play the roles that scales play for the solo improvisations!
(see also post 17 and post 32)

We enlarge more on it.

A GOOD IMPROVISED OR COMPOSED CHORD PROGRESSION X(1) X(2) X(3),...X(N) IS ONE THAT HAS ONLY THE NEXT 3 CHORD-TRANSITIONS

1) X(I)->X(I+1) IS RESOLVING , THAT SUCCESSIVE IN THE WHEEL OF 4THS
OR  ANY OF THE TWO HAS BEEN SUBSTITUTED WITH RELATIVE CHORD OF IT WITH 2 COMMON NOTES (ALTERNATING MINOR TO MAJOR OR VICE VERSA)
OR
2) X(I)->X(I+1) ARE RELATIVE CHORDS WITH 2 COMMON NOTES, ALTERNATING MINOR TO MAJOR OR VICE VERSA (SUCCESSIVE IN THE WHEEL OF 3RDS)
OR
3) X(I)->X(I+1) HAVE ROOTS IN DISTANCE OF ONE SEMITONE OR ONE TONE (SUCCESSIVE IN THE WHEEL OF 2NDS)

An example of such a chord-progression improvisation is the next progression, that can be played from the 4th neighborhood of the guitar to the first open chords neighborhood

Em->G->Bm->Bb->F->E7->Am->D7->Em->G->D->F#m->F->C->Em->D#->Bb->A7->D

Now we can extend these rules and at the same time simplified them for guitar players. We always assume playing only on the higher 4 strings of the guitar, and the chords are essentially the triads played  only on the 3 higher strings.

A GOOD IMPROVISED OR COMPOSED CHORD PROGRESSION X(1) X(2) X(3),...X(N) IS ONE THAT HAS ONLY THE NEXT 2  CHORD-TRANSITIONS:

1) WHEN THE CHORDS ARE DISTANT IN DIFFERENT OCTAVES, THEN THE CHORD TRANSITION    X(I)->X(I+1)  MUST BE EITHER A) RESOLUTION AS SUCCESSIVE CHORDS IN THE WHEEL OF 4THS B) RELATIVES (ALTERNATING MINOR TO MAJOR AND VICE VERSA) AS SUCCESSIVE CHORDS IN THE WHEEL OF 3RDS. IT IS SUGGESTED THAT THE TRANSITIONS AS SUCCESSIVE CHORDS IN THE WHEEL OF 4THS ARE MUCH MORE THAN THE TRANSITIONS AS RELATIVE CHORDS

2) WHEN THE CHORDS, AND THEIR EXACT VOICING ON THE FRETBOARD, ARE IN THE SAME OCTAVE (AND WE DO NOT REDUCE THEM TO EQUIVALENT IN THE SAME OCTAVE) THEN THE CHORD TRANSITION X(I)->X(I+1) MUST BE SUCH THAT THEIR SHAPES AS PLAYED HAVE AT LEAST ONE FRET IN COMMON (MAYBE 2 OR 3 COMMON FRETS TOO AND MAYBE ONE, OR TWO NOTES IN COMMON). IT IS SUGGESTED THAT THE TRANSITIONS AS SUCCESSIVE CHORDS IN THE WHEEL OF 4THS ARE MUCH MORE THAN THE TRANSITIONS AS RELATIVE CHORDS AND THE REST OF THE TRANSITIONS AS CHROMATIC TRANSITIONS WITH ROOTS ONE OR TWO SEMITONES APART, OR ONE ONLY COMMON FRET ARE MUCH LESS IN NUMBER. ALSO IF JOYFUL SONGS ARE INTENDED THEN AT LEAST 2/3 OF THE CHORDS ARE TO BE MAJOR AND  LESS THAN 1/3 MINOR CHORDS. IN ADDITION THE PATTERN OF CHORD TRANSITIONS AS OF THE 3 BASIC TYPES MUST SOMEHOW REPEAT IN THE CHORD PROGRESSION EVEN WITH DIFFERENT CHORDS.

3) BASED ON THE IMPROVISED CHORD PROGRESSION, THEIR ARPEGGIOS DEFINE AT A SECONDARY ORGANIZATION LEVEL SECONDARY MELODIC AND SOLOING IMPROVISATION AT THE LEVEL OF NOTES NOW AND NOT CHORDS!

NOW WE DO NOT NEED TO PLAY ALL THE CHORDS OF AN IMPROVISED CHORD-PROGRESSION WITH EQUAL SIGNIFICANCE OR TIME DURATION. SOME CHORDS MAY BE GHOST-CHORDS

GHOST-CHORDS PROGRESSION METHOD OF IMPROVISATION OVER A SINGLE CHORD:

MOST OF THE TEACHERS OF IMPROVISATION SUGGEST  USING THE ARPEGGIO OF THE UNDERLYING CHORD, EITHER AS PURE TRIAD OF NOTES OR AS EXTENSION TO 4 OR 5 NOTES SUCH CHORD. BUT THERE IS ANOTHER INTERESTING TECHNIQUE THAT INVOLVES GHOST-CHORDS (NAMELY THAT ARE NOT REALLY HEARD). E.G. OF WE ARE TO IMPROVISE SAY ON C MAJOR CHORD, THEN IT IS NOT ENOUGH TO USE ITS ARPEGGIO, BUT DO THE NEXT: CONSIDER C IN THE CHORD PROGRESSION OF THE SONG, AND TAKE TWO OTHER CHORDS OF THE SONG PREFERABLY IN THE WHEEL OF 4THS,  THE 2 NEIGHBORHOOD CHORDS (EITHER AS MAJORS OR MINORS) HERE E.G. LET US TAKE THE MAJORS G->C->F ASSUMING THEY WHERE IN THE SONG. IF THERE IS NOT SONG YET WE JUST TAKE . IN THE WHEEL OF 4THS,  THE 2 NEIGHBORHOOD CHORDST (that define here the C major-mode diatonic  scale) . THEN  TAKE THE ARPEGGIOS OF THESE THREE CHORDS AND PLAY THEM IN RHYTHMIC , FAST AND RATHER RANDOM PERMUTATION  WAY, AS IF A VERY FAST CHANGE OF CHORDS IS MADE IN THE THREE  G->C->F, SO FAST THAT G, F CHORDS ARE RATHER TRANSIENT WHILE WE REMAIN MOST OF THE TIME ON C. THE SEQUENCE OF THE CHORDS THROUGH THEIR ARPEGGIOS DEFINE ALSO A SOLOING. THE RESULT WILL BE AN IMPROVISATION ON ALMOST A WHOLE 7-NOTES SCALE, WITH UNDERLYING SINGLE CHORD THE C.IN ADDITION THE SOLOING TAKES IN CONSIDERATION   AT LEAST TWO  OTHER CHORDS OF THE SONG. IF THERE IS MELODY IN THE SONG WE MAY CONSIDER MIMICKING THE MELODY WITH WAVINGS AND "DANCING AROUND THE NOTES OF IT, IN NOTES THAT EXIST IN THE CHORDS OF THE MELODY. OR WE MAY APPLY DIFFERENT TRANSFORMATIONS IN THE MELODIC THEMES THAN THE TRANSFORMATIONS THAT EXIST IN THE MELODY. THE RESULT WILL BE A DIALOGUE BETWEEN THE MELODY AND THE SOLOING

The diatonic progressions is the sequence (iii->vi->ii->V->I->IV->VII->iii), This progression leads from sadness to joy, from the triad of minor chords to the triad of major chords. In the symbolism of the 24-cycle of  chords the diatonic scale is the arc of the next chords   (x-2, X-1,x-1,X,x,X+1,x+1)=(vii,V,iii,I,vi,IV,ii). (see post 34). 

There is also the inverse or descending  diatonic progression which is the (I->V->ii->vi->iii->VII->IV->I)

In a diatonic scale, the triad of minor chords (sad triad) is the (iii->vi->ii) where the (iii, vi) and (vi,ii) are consecutive in the cycle of pure 4ths, with standard resolutions (iii7-> vi) , (vi7->ii) and the 
(ii, iii) are complementary chords, in other words all of their notes give all the notes of the scale except one. 

The triad of joy or triad of major chords  is the (V, I, IV) , where the (V, I) and (I,IV) are consecutive in the cycle of pure 4ths, with standard resolutions (V7-> I) , (I7->IV) and the  (IV, V) are complementary chords, in other words all of their notes give all the notes of the scale except one. 

The bridge between these two triads is the well known jazz progression (ii7, V7, I) , where again  the (ii, V) and (V,I) are consecutive in the cycle of pure 4ths, with standard resolutions (ii7-> V) , (V7->I), and  the  (ii, I) are complementary chords, in other words all of their notes give all the notes of the scale except one. 



Alternative closures 
The diatonic progression closes also to a cycle by utilizing the triad progressions 
(IV->IV#7->VII7->iii) or (IV7->VIIb->vi). 
Or IV->V7->I or IV->ii7->V7->I
Or IV->IVdim7->G7->I   (see e.g, Bach prelude and Fugue C major, BWV 846)
Or IV->IV#dim7->VII7->iii


HERE IS THE 24-CHORDS CYCLE IN THE REVERSE ORDER BY 5TH RATHER THAN BY 4TH WHICH IS THE ACTUAL 

WHEEL OF 4THS
1) The short 3-chords sub-cycle of the wheel of 4ths is a set of chords X1, X2, X3 where the previous chords are successive in the wheel of 4ths but they may be either minor or major and alternating also. Thus there are 2^3=8 types of such small sub-cycles. Essentially they define a diatonic scale or a mode of it

2) The medium size sub-cycle is a sequence of 6-chords X1, X2, X3, X4 X5, X6,  which they are again successive chords in the wheel of 4ths and again they may be either major or minor or alternating in any combination (e.g. two successive minor then one major etc).For this to be a sub-cycle, the X1, and X6 must differ in their root notes only a semitone.  For the choices of major or minor there are 2^6 such types of sub-cycles. We may also add the possibility that they are dominant 7tnth or major 7nth chords, or chords with 6th etc.

3) Similarly the 4 or 5 successive chords in the wheel of 4ths  X1, X2, X3, X4 X5 maybe considered closing if X5 and X1 ar relative chords e.g.

Bm->Em->Am->Dm->G, as G and Bm are relative chords

But also the 4-chords sequence is also

Em->Am->Dm->G, as G and Em are relative chords.

1) The minimal 3-chords cycle.
This is 3 successive chords in the wheel of 4ths

e.g. G->C->F->G
or Em->Am->Dm->Em.

Slight enlargement to this is the  Small 4 chords cycles of relatives mutation (by // we denote the relatives mutation)

Examples:  A->D->G//Em    or D->G->C//Am    or   G->C->F//Dm

2) Medium  6 chords cycles of chromatic mutation (by // we denote the chromatic mutation)

Examples:  A->D->G//F#->Bm->E    or A->D->G//F#->B7->Em

or  A->D->G->C->F->Bb//A

D->G->C//B7-> Em->A7  or D->G->C//B7-> E->Am

G->C->F//E7->Am->D  or G->C->F//E7->A->Dm

o

(Notice here that if we would restrict to a diatonic scale the cycle G->C->F//E7->Am->D  or G->C->F//E7->A->Dm   would be

G->C->F//Em7->Am->Dm  .

This cycle can be extended to an 8-cycle in the following way:

The 6-cycle  A->D->G->C->F->Bb//A  can be extended to the 8-cycle

A->D->G->C->F->Bb->D#->Edim7->A

or the A->D->G//F#->Bm->E  will become A->D->G->C->C#dim7->F#->Bm->E

With double chromatic mutation we have the progression 7-chords cycles

A->D->G//C#->F#->Bm->E  or D7->G7->C7->F7->Bb//E7->A7, which also can be alternating in minor major: Dm7->G7->Cm->F7-<Bbm//E7->Am7  or D7->Gm7->C7->Fm7-<Bb//E7->Am7 etc.

See also the double Andaluzian cadenza above and the standard Jazz 7-chords progression

So the  suggested cycles already contain a modulation that combines e.g. two diatonic scales o a diatonic and a harmonic minor etc, and is necessary so as to have 2/3 or more major chords in the chord progression. So the rule is: The 2/3 rule of major chords in the chord progression of 6 chords necessarily   involves modulations, and cannot be conducted within a single diatonic scale!!!

C->F->Bb//A7->Dm->G or C->F->Bb//A7->D->Gm

etc.

Notice that an alternating even only or odd only sequence of chords in such 7 chords cycles with double chromatic mutation gives the Andaluzian cadenza and Jazz 7-chords progression.

Example of  beautiful chord progressions that one can obtain with the above 6 or 7 chords cycles are the next with the next rules

1) All chords are from the above 7-cycle cycle with chromatic mutation and are with 7th chords

2) Any two successive chords are either successive in the above cycle ( that is successive in the wheel of 4th too or are in chromatic 1 semitone relation) or are relative chords, or inverses in order in the above relations

3) All successive chords alternating are minor then major or major then minor.

4) There is a starting and ending pair of chords which is successive in the wheel of 4ths and are both major chords.

An example of a chord progression with the above rules is the next

C7 F7 Bbm A7 Dm7 D7 Gm7 C7 Am7 D7 Gm7 C7 Am7 Bbmaj7 A7 Dm7 D7 Gm7 C7 Am7 F7 Dm7 A7 Am7 D7 Gm7 C7 F7.

When playing such chord progressions we may move slowly all the way  up and then all the way down in th fretboard.

3) Full 12 chords cycle: A->D->G->C->F->Bb->D#(=Eb)->G#(=Ab)->C#(=Db)->F#->B->E

where at most 1/3 that is at most 4 chords can be minor chords.

WHEEL OF 3RDS

SOME EXAMPLES OF THE SMALL AND MEDIUM SUB-CYCLES

The next sequence of intervals  (3333444)=(C,D#,F# ,A,C,E,G#,C) defines a   closed cycle of 4 relative chords:   Cdim7, Am ,Eaug, G#7=Ab7 They sound  resolving in the next sequence Cdim7 Eaug  Ab7  Am



The next sequence of intervals  (3334434)=(C,D#,F#,A,C#,F,G#,C) defines a   closed cycle of 7 relative chords: Cdim7, D#dim, F#m, Aaug, C#, Fm, G#




The 7-chords diatonic closed cycle of relative chords is the  (4343343)=(CEGBDFAC):
C, Em,G, Bdim, Dm, F,Am

The 24-chords chromatic closed cycle of relative chords (434343434343434343434343):

G        C         F         Bb          Eb        Ab         Db          Gb          B           E           A         D             
     Em   Am     Dm        Gm       Cm       Fm        Bbm       Ebm     Abm     Dbm     Gbm   Bm  


We may add two more series based on that mnot-major chords with the same root are relative chords too, so as to havea 2-dimensional grid based of the relation of relatives.


Gm    Cm       Fm        Bbm       Ebm     Abm     Dbm     Gbm   Bm     Em       Am     Dm  
G        C         F         Bb          Eb        Ab         Db          Gb          B           E           A         D             
     Em   Am     Dm        Gm       Cm       Fm        Bbm       Ebm     Abm     Dbm     Gbm   Bm  
     E        A         D           G        C              F         Bb            Eb        Ab         Db         Gb      B  

This grid which is also a table as below shows clearly the chords that are  harmonically in series(interval of 4th or 5th) and chords that are harmonically in parallel (intervals of 3rds or 6ths). But it does not show of course the relations of chords that are melodically in series

Gm

Cm

Fm

Bbm

Ebm

Abm

Dbm

G

C

F

Bb

Eb

Ab

Db

Em

Am

Dm

Gm

Cm

Fm

E

A

D

G

C

F

	Gbm		Bm		Em		Am		Dm
	Gb		B		E		A		D
Bbm		Ebm		Abm		Dbm		Gbm		Bm
Bb		Eb		Ab		Db		Gb		B

It is often very instructive to chart the chords of  a  song over this 24-cycle of relatives (or double cycle of 4ths) or the above 2-dimensional grid.

Most often a song is a sequence of connected intervals or arcs of chords in the cycle of 12ths shifting by relatives to a corresponding similar connected arc in the parallel cycle of 4th in the overall cycle of fifths. We call this concept a harmonic multi-tonality. Simple  tonality is simply 3 -successive major chords in the 12-cycle of 4ths. 

Conversely any connected sequence of arcs of chords of this 24-cycle of chords (defining harmonic multi-tonality), is the chord progression  of a nice song with nice sounding modulations. Normally in harmonic multi-tonality  we are keeping the qualities major-minor as in the 24-cycle but a more free approach allows altering them , from minor to major and vice versa or to more complicated qualities like 7th, 6ths etc.  The same for chord progression for improvisation (see post 11) . To the rule of harmonic multi-tonality in the 24-cycle, we may allow as transition to a next chord, a shift by one semitone or tone of the root of the current chord. (see also post 30)

See also https://www.youtube.com/watch?v=TRz73-lSKZA


TO ACCOMMODATE A SCALE OF CHORDS ORIENTED IMPROVISATION METHOD, A SPECIAL TUNING FOR THE 6-STRING GUITAR CAN BE GIVEN THAT REFLECTS THE WHEEL OF 3RDS.

OPTIMAL GUITAR TUNING FOR CHORDS PLAYING MAINLY

1.) An more optimal but unknown tuning for the 6-string guitar when chord-playing is the main target and not so much solo playing is and even better by alternating minor and major 3rds. In semitones for the 6 strings   4-3-4-3-4 or 3-4-3-4-3
E.g. Bb2- D3-F3-A3-C4-E4 or F2-A2-C3-E3-G3-B3 or A2-C3-E4-G4-B4-D4
THIS MAY BE CALLED THE HARMONIC TUNING OF THE GUITAR AS IT IS BASED ON THE HARMONIC 2-OCTAVES 7-NOTES SCALE (see also post 79)
The latter is the most natural open tuning. There the same shape for major and minor chords and only 3 of them and in only one or frets compared to the 6 in the standard tuning guitar. If we want also dominant and major 7nth chords we use again only 2 frets. The same with the aug chords Only the dim7 chords require 3 frets. Because  of the symmetry of the tuning among the strings, the relations of relative chords and also chords in the wheel of 4ths is immediate to grasp also geometrically. Of course when we say shape of chords as it is standard in jazz, we do not play all 6-strings but only 3 or 4 strings.
Within 3 frets exist all chords of the  8-notes scale with interval structure 2-2-1-2-2-1-1-1 which is an extension and variation of the melodic double minor 2-2-1-1-1-1-2-2 or (1-1-1)-(2-2)-(2-2-1)

But also all chords of diatonic scale!

The easiness with which one can improvise melodies within a diatonic scale (all notes within 3  frets and in a very symmetric zig-zag pattern) together with 3-notes chords of the scale (gain all chord patterns within 3-frets) is ussuprassed.
At the same time , the easiness with which one can me diatonic scale modulations, chromatic (1 semitone apart) or by changing a minor to a major chord and vice versa and contiuining in a relevant diatonic scale is unsurpassed again! 

Let us make some remarks at first about classical 4-voice harmony, fugue contrapuntal, and harmonic cannons. This strictly speaking is considered historically as pro-classical music that is almost the only music that was in fashion before the 18th century.

Classical 4-voices harmony is based roughly speaking on the idea, of writing 4 melodies within a diatonic scale so  that the 4 voices make either a chord triad (one note repeats) or a 4-chord (7nth) of the diatonic scale. So instead of having one instrument playing the chord and a second playing the melody, we have 4 instruments that only all together they play the chord, while each one is playing a melody.
Nevertheless, this means that the voices are 3 or 4 semitones apart (interval of 3rd)
so all pitch dynamic patterns are similar (with some small exceptions when 2nd 3rd and 4th voices exchange roles). This may seem poor freedom in the pitch and rhythmic dynamics of the 4 melodies. 
The next step in this freedom is the fugues contrapuntal (e.g. as in J. S. Bach). Here each voice or instrument is playing its own melody,  with different morphological pitch dynamic pattern from the rest of the 3 other voices. (For morphological pitch dynamic and rhythmic patterns see posts 18,19). Usually, a melodic pattern is started from one of the voices and it is passed to another voices and so one. While one voice is playing the melodic pattern the other 3 add less in number notes and without the rhythmic pattern of the melodic pattern so that a 3-notes or 4-notes chord is shaped, and still all voices play different morphology of melody. Or while a voice is playing the melodic pattern the other voices do not sound at all or only another voices is sounding. It is very easy to modify slightly the 4 voices so most often either only one sounds at each note , or only 2  sound , in an interval of the used scale or they move fast with many notes in which case the ear does not hold harmony, and rarely when all three or four have notes that sound simultaneously, called centers of the melodies because the sound longer than the other notes, then it is always a 3-notes chord or 4-notes chord of the scale. If an initial chord progression is not defined in advanced this is easy to design  for the 3 or 4 voices-melodies. But even if an initial chord progression is introduced it will become easy if we allow for chord repetitions and probably extension with more chords (Chord butterflying).Of course it may be easier to create at first one melody, then vary it without changing its centers to different melodies with different morphology, and then put them together according to their centers and the chord progression , possibly modifying them slightly. In other words the greater freedom of the 4 voices requires that  they shape 3-notes or 4-notes chords only at selected notes that sound usually longer and not always. Another simpler idea is to take only the basic theme of the melody, and create many simultaneous  harmonic variations of it (extrapolated refinements) that when played simultaneously create at the centers different chords of the scale and of the chord progression. Do it for all the chords in the progression and label all the pieces according to the chord. Then combine in sequence the theme and its variations according to their harmony and the order of the chords in the chord progression, and pass the theme to another voice when the variations of the first voice sound, and continue with variation pieces according to the following chords. And the same with all the other voices. If one is sophisticated he even create the same theme in different time scales (like  a fractal) and thus embellishes harmonically the larger theme with itself in shorter time scale.  When Bach was creating his fugue the music composition based on chords was not popular or well understood, but nowadays we can create easier fugue contrapuntal with chord progressions. An additional element that connects now the 4 voices is not the harmonic union in a  3-notes or 4-notes chord of the scale but the passing from a voice to another of the central melodic pattern which repeats like a phrase in a dialogue of 4 people that repeat it non-simultaneously. See e.g. 
https://www.youtube.com/watch?v=RAP5fL84sKw
https://www.youtube.com/watch?v=HohFSu9H49A
https://www.youtube.com/watch?v=7S2pm1g70DI

Concepts of J.S. Bach compositions

http://www.lchr.org/a/5/ax/bach_concepts.htm

A more symmetric idea is that of a Harmonic cannon which is in between the classical 4 voice harmony of 4 -voices with the same pitch dynamic pattern and the freedom of a fugue . In the harmonic cannon the 4 voices are intended to be almost the same but they  start at different times with a delay of each relative to the other.

See e.g. https://www.youtube.com/watch?v=NlprozGcs80

We summarize the basic concerns in the melodic improvisation and composition of a voice or melody  (similar to the syntax of phrase with subject verb and object etc).

1) Always use a finite set of melody motives, themes or moves. A theme may consist of the basic 4 melodic moves.  (The theme entity for melodies is so important as the chord in harmony. A theme can be inside a chord or over a chord transition. Conversely, any of the 3 types of chord transitions may define a theme for the melody, thus a finite set of themes for a chord progression)
2) Transform these melodic themes or moves  which will be the invariant of their transformations. The simpler the themes the easier the transformations.
3) Close by returning to the initial theme. 
The ways to transform a theme are at least the next 5 and combinations of them
1) Translate it in different pitches (within a scale or not changing possibly the pitch distances )
2) Translate in time (repeat it)
3) Invert it in time or change its rhythm (if at the begging is slower and at the end faster it will be now the reverse etc)
4) Invert it or distort it in pitch (Create 1st 2nd 3rd or 4th voice versions, utilizing the chord progression as rules of transformation of the theme, or if it is ascending now it will be descending etc)

5) Change it as morphology  (from a non-waving ascending it may become waving ascending or iso-kratic) . We prefer spikes and scaling as  the main  morphological types, while the waving and isokratic as intermediate bridges. 

The themes of a melody consist of a plot or sequence of the 4 basic moves (see post 59)  which by itself says an emotional story without the help of the harmony. If we have (as here we assume we do) an underlying chord progression, then utilizing almost all the notes of the chords and one theme for each of the 3-harmonic-types of chord transitions , we may define the set of themes of the melody in easy way. Alternatively we may define a theme for each type of emotion, sad, joy, anxiety or serenity, or a theme for each type of chord respectively minor (sad) major (happy), 7nth or diminished or augmented (anxiety) and r5 (serenity.) The chord progression serves as a way to transform and make variations of the themes. The notes of the simplicial submelody are the centers of the melody that sound longer and are usually the tops and bottoms of the 4 basic melodic moves that create the themes of the melody but also the notes of the underlying chord. 

A very useful remark for improvisation of melody within a particular chord is the next.
Suppose we are at a note y1 of the melody which fits the underlying chord with notes x1x2x3 (whatever that may mean), then depending on the particular position of y1 relative to the x1x2x3, a shift by an interval of 3rd, 4th, 5th, and 6th wil lead to a note y2 that will again fit the chord!. This is because the relative positions of the notes x1x2x3 of the chord are intervals of major, minor 3rd and pure 5th, and their complementary intervals relative to the octave are minor or major 6th, and pure 4th 

Summarizing in  a simplistic way the correspondence of melodic pitch dynamics and the 4-basic emotions in music (joy, sadness, anxiety, serenity) we have 

1) Up pitch moves correspond to joy

2) Down pitch moves to sadness

3) Small pitch intervals of 1 or 2 semitones (chromatic or interval of 2nd) correspond to anxiety

4) Large pitch intervals (e.g. 4th, 5th octave etc) correspond to harmony and serenity. 

Some instructive remarks in the composition of the melody based on the chord progresion

1) In the part of the chord progression with minor chords, utilize descending melodic moves so that sadness from melody and sadness from harmony fit
2) In the sad melody parts of the melody (and minor chords) utilize rhythmic patterns that start with faster notes and end with slower notes, and the reverse for the happy part (and major chords).
3) In a triad or 7 nth 4-notes chord the most characteristic notes are the middle 2nd note (in 1-3-5 interval notation  is the 3) and the 7 nth (if it exists). So for the anxiety part of the melodic moves we may utilize 1-semitone trills around these two notes, or waving with 1 or 2 semitones steps and notes outside the chord in the interval of minor 3rd (3 semitones) of the chord. Alternatively instead of trill or small amplitude waves we may utilize chromatic monotone scaling by steps of 1 semitone , or scaling with steps by intervals of 2nd of the scale,  that go from these previous notes of the chord to the same such notes in the next octave. But always make sure that the notes of the chord sound in the average longer, than the notes of these anxiety transition moves with notes outside the chord. 
4) Alternate up (happy) and down (sad) pitch moves , or chromatic moves (anxiety), with harmonic (on chord notes) moves (serenity-harmony).
5) Utilize at least 2 octaves, or even 3 for the melodic moves repeating the notes of the underlying chord on the next octaves , so there is sufficient space for melodic moves, to express with sufficiency the emotions.
6) For the duality of emotions anxiety-serenity, it may be utilized also harmonic waves or monotone scaling over 2 octaves at least,  on the notes of the chord, but also chromatic trill wave over the notes of this wave or scaling (modulated wave on wave or move) and then return to the pure harmonic wave or scaling on the notes of the chord.



7) A chromatic wave by 1-semitones steps or all notes of the scale (steps by intervals of 2nd) that goes up and down at least 2 octaves, corresponds to a chord sub-progression of the song , of our choice that utilizes almost all the chords of the scale!

For the correlation of melodies with chords that fit to them, or conversely , melodies that can be improvised over a chord progression the next local concept is very significant: The closure of a chord: This is defined as the closed interval of notes from all the 12-tone (chromatic) scale) with lower end the lowest note of the chord, and highest end the highest note of the chord. The chord is assumed within an octave, and normal positions, 1st inversion, and 2nd inversion have different closures. It holds the next interesting theorem. If we define randomly a melody within a the closure of a chord  in normal position  and no other note outside it, with uniform probability of occurrence of any of the notes of the closure, then according to the local condition of fit of a piece of melody with a chord  the only chord  in normal position  that would fit this melody is the one with this as its closure!. Or more generally of we  define  as probabilities of sounding a note on all the octave an equal value for all notes    except at the notes of the chord X where we have as probability the double this value (e.g. sound each note of the octave once as a scaling that covers all the octave but also the notes of the chord once more by just harping the chord) then any such random melody with this probability structure will have as its fitting underlying chord the chord X. 


After the chord progression and simplicial submelody we chose, 
THE DEFINITION OF MELODIC BRIDGES THAN LINK TWO SUCCESSIVE CHORDS BETWEEN THEM AND START AND END AT THE NOTES OF  THE SIMPLICIAL SUBMELODY.

1) WHICH CHORD-TRANSITIONS (PAIRS OF CHORDS) WILL HAVE A MELODIC BRIDGE! (Usually the chord-trasnitions that are in resolutional relation, or resolutional-like relation)

2) THEN WHICH BRIDGES WILL BE ISOMORPHIC IN PITCH AND RHYTHMIC DYNAMIC SHAPE AND WHICH DIFFERENT, DEFINING THEREFORE A PARTITIONING IN THE BRIDGES.

3) THEN IF IN EACH EQUIVALENCE CLASS OF  ISOMORPHIC MELODIC BRIDGES IN THIS PARTITIONING, THE BRIDGES ARE  EVENTUALLY ASCENDING OR DESCENDING (This besides the emotional significance, determines also where to play the chord in one of the 3 neighborhoods of the fretboard)

4) FINALLY  HOW IN EACH EQUIVALENCE CLASS OF  ISOMORPHIC MELODIC BRIDGES IN THE PARTITIONING, THE COMPLICATED PITCH DYNAMIC SHAPE  OR WAVING AND RHYTHM WILL BE AS A REPETITION  OF SUCH PATTERNS OF PREVIOUS ISOMORPHIC MELODIC BRIDGES, OR VARIATION OF  SUCH PATTERNAS S SO NOT TO BE TOO BORING. (This pitch dynamic shape has again a significant emotional meaning)

Musical improvisation is not a technical skill that one “learns to do.” It is a natural
spontaneous process that occurs at first in the imagination.

There are 3 types of improvisation as far as the interaction of chords and melody is concerned.
1) Melody only improvisation, when the chords are known and are played by another musician or the band.
2) Alternating melody and chord sounding in the melody improvisation, played by the same guitarist (It is easier when the chords are known in advance).
3) Simultaneous sounding of chord and melody played by the same guitarist.  It is easier when the  essential underlying chords are known in advance. But if we count the chord plus melody as a new composite chord, the unpredictability of the melody makes the composite chords unpredictable too. This is called Chord-melody improvisation, and when observed it looks like a new chord (the composite chord of chord+melody) is playing one every note of the melody, or as a melody of chords. 



SIMULTANEOUS BASS-CHORD-MELODY IMPROVISATION (David Reed)

(As we utilize only 4 fingers of the left hand, the 3 of them always sound the bass and the chord, while the 4th the notes of the melody, that may or may  not belong to the chord.)

In his book "Improvise for Real" David Reed, strongly suggests to investigate by improvisation the 4 types of chords Rmaj7 (in semitones 1-4-7-11), Rm7 (in semitones 1-3-7-10), R7 (in semitones 1-4-7-10), Rm7b5 (in semitones 1-3-6-10), with parallel melodies, always on higher pitch relative to the highest pitch note of the chord. For harmony beyond tonality, the appropriate numbering of the notes of a diatonic major scale measured with semitones is 1-2-4-5-7-9-11 |  1. David Reed suggests that utilizing the relative numbering rather than the specific name of the note (and he is mainly utilizing the numbering as a major diatonic scale 1-2-3-4-5-6-7 | 1), the mental tools in the human imagination are kept simple and directly applicable on the frets of the guitar fretboard or the buttons of the piano keyboard. In simpler words he insists in re-creating the desired harmony , by intervals and triads from chords  for the melody and the chords
This chord-melody  technique is by far more abstract, thus powerful. It is not based on memorized chord-shapes!  The chord-shapes are continuously changing even for the same chord inside and area of 4-5  frets and are created on the going with the melody!  Both the melody is played but at the same time the chord behind the melody too. It is  played so that the melody is always the highest pitch note, the root of the chord the lowest pitch note, and the 2 intermediate notes again notes of the chord. One finger is used for the melody and 3-fingers for the chord. It is always sounding at most 4 notes, of 4 strings.  Notice that finding and playing these fingerings of e.g. 1st chord Cmajor  harmonizing any note of the C major scale, from higher C to lower C, is not the same as just finding the fingerings of the chords Cmaj7, C7, C6, Cadd11, Cadd9, because of the condition of having the note of the melody always the highest pitch,  the root  unchanged as fret position and because we descend 2 octaves rather than one. Most of the times the resulting chord may not have any known symbol, and so also its shape may not be any known chord shape. Nevertheless the classification of the fretboard shapes of the 8 types of chords as in post 28 and of  triads as in post 38, is useful in practicing this type of beautiful chord-melody improvisation. From the next videos that describes this techniques of improvisation called chord-melody, we may deduce that the chords behind the melody are always of one of the next 4 types: Rmaj7, Rm7, R7, Rm7b5.  Of course we can restrict the technique to have background chords for the melody only R, Rm, with one (or rarely two) notes (but never the root) each time missing and substituted by the note of the melody. This would be improvisational classical 4-voices harmony, and the  post 39 is devoted to it. We may also change the background chord in such a way, that the note of the melody is always also a note of the chord. For this the classification of shapes in post 38 is useful. In other words we may make sure that the 4-string chord-melody is such that the utilized chord types are of some only specific set e.g. Only R, Rm 4-string chord melody. This would be improvisational classical 4-voices harmony on 4-strings , and the  post 39 is devoted to it. Or only Rm7b5, R ,4-string chord melody, or only Rmaj7, R7 4-string chord melody etc.
In general though David Reed suggests that we play and improvise  as melodic notes any note of the diatonic scale for any chord of the diatonic scale!  It seems to me that the only requirement that binds the arbitrary chord with the arbitrary melodic note of the diatonic scale, is that the melodic notes that belong to the chord as a total last in time longer , say 2/3 of the time , while any other arbitrary note of the scale, only 1/3 of the time. 
 For this wonderful technique see e.g. 

https://www.youtube.com/watch?v=binjvIqAN1s
(https://www.youtube.com/watch?v=cAxB5bQfF5s
https://www.youtube.com/watch?v=R-P06FDk4NA)

https://www.youtube.com/watch?v=NtsHxjeEgBw

https://www.youtube.com/watch?v=yxeOjqNK2Cw

The channel and sites are the next
https://www.youtube.com/channel/UCz83VW6dQLvAdUeZg9IDTHg

https://improviseforreal.com/Products/ifr-video-course-guitar-module-1


Also see https://www.youtube.com/watch?v=hSF-SVi-d1o

For the 4-string ukulele here is how chord-melody is done

https://www.youtube.com/watch?v=0Se5w7Kio2w
https://www.youtube.com/watch?v=VYqtQ_MXtnw

and 

https://www.youtube.com/watch?v=PEzhEMIZJ5s
https://www.youtube.com/watch?v=HCZXVKmNi_g

Hint about melody improvisation.

If a base chord is e.g. the 1-chord R 1-3-5, then we may start 1 octaves higher and experiment with descending melody notes 7, 6, 5,  and 4,3, 2,1  in the 2nd octave producing thus sounds of composite  chords   Rmaj7,  R6, R ,Radd11, R Radd9, R . As Radd9, Radd11 sound less well than Rmaj7, R7, R6, R, we may set the restriction that the note of the melody and the backround chord , can make a composite chord which is only one of the next types of chords: R, Rm, R7, Rmaj7, Rm7, Rm7b5.  It is easy to verify that as all the 1,2,3,4,5,6,7 , 3-notes chords of the diatonic scale  are of type R, Rm, Rdim , for any note of the diatonic scale it is always possible to chose one of the 7  chords of the diatonic scale, such that the Composite Chord=Chord+melody note is always one of the above types of chords  (R, Rm, R7, Rmaj7, Rm7, Rm7b5). In fact it could be only of the type (R), that is always  a note of the chords 1,4,5   or (R, Rm) or (R, Rm ,Rdim) , that is again a note of a chord of the scale.

Here is  a very simpler but also beatiful way to create chord-melodies from chord progressions. The melody is a simple oscillation (waving or butterflying) around the highest note of the chord with intervals of 2nd or 3rd. We may emnhance this method by  chosing different inversions of the same chord so that the desired note is always the highest in the chord. 

https://www.youtube.com/watch?v=YBkIDXscSCo


See also https://www.youtube.com/watch?v=olksbLorpIY

and Allan Holdsworth perceptions.

Allan Holdsworth  is using chords defined by the notes a scale and having notes strictly inside the scale , but when  the scales are not the diatonic scale, the chords, may be quite weird. An alternative and more  Harmonic approach is described in post 27, and is the concept of chords COVERING a scale (that the chords may contain notes outside the scale). This approach is much more flexible, and we may choose chords of any good classical type e.g. only major, or only minor major, R5 etc 

https://www.youtube.com/watch?v=7h-MdM7JCGs

In the next we describe how the identification of chord-transition melodic moves, defines also, a way to alternate soloing and chords which is chord-melody improvisation.

We have described in post 9, 63, 67 how chord-transition melodic moves can be composed. We summarize.

We may define melodic moves not for each chord but for each chord-transition, and preferably for the        X7-->x+1 type of transitions (see the symbolism of post 34) e.g. E7-->Am.

Then the chord X7 has only one note x1 for simplicial submelody  the starting note of the melodic move, and the end note x2 of the melodic move is the next simlicial submelody note and one note of the chord x+1 not common with the chord X7. If the latter note x2 is not the root of x+1, it is created a tension that has to be resolved later where x2 would be the root of x+1. In between the x1 and x2, the rule is that at least 2/3 of the notes belong to the underlying chord, and this can be achieved by repeating notes of the underlying chord if necessary. The move x1->x2 may involve  each of the chords X7, x+1 , twice in two octaves each instead of once in one octave only, which may create very impressive melodic effects. This gives an even better opportunity to use in the melodic move, intervals of 8th, 4th and 5th (high harmonic speed, see post 68) , that have higher harmonic score than the other intervals (see post 40). The at most 1/3 of the total duration of the move x1->x2 ,of notes that play with underlying the 1st chord but may be outside the starting chord, might be unusually at chromatic and diatonic speed (see post 68), and sometimes might belong to the next chord or even to none of the two chords. The melodic moves x1-->x2 can be called chord-transition melodic moves and must have an element of repetition in length and rhythm.  
In the transitional Irish melodies that utilize 2-3 only major chords, while the melodic moves are 4-5 or 6-7 , but also in the traditional Greek music of the Aegean Islands, the starting and ending point of the melodic move is during the duration of a single chord and are notes of the chord! But still the rule 2/3 -1/3 for notes internal and external to the chord still holds, and the starting and ending notes of the melodic move may define the simplicial submelody.

In this way of composing chord-transition melodic moves, the starting ad ending points are of paramount importance. Generally speaking, they are not identical with the centers of the melody, as they do not last in general longer than the other notes. They can be used though to define the simplicial submelody.    

By substituting the melodic move with its starting and ending notes we get a simplicial submelody, which shows in a simplified way the general move of the melody as a whole, whether it is ascending or descending and how much, and how this is done based on the 3 notes of each of the underlying chords. 

In the harmonic method of composition (see post 9) we conversely start with the chord progression, and its chord transitions, we select the starting and ending points of the melodic moves, and then  the morphological type of the melodic move , their length , their  rhythm , harmonic speeds etc. 

The chord-transitional melodic move is as a generalized interval which is defined by the starting and ending notes of the melodic move (and which belong respectively to the starting and ending chords of the chord transition). 

In the example below the chord progression is Am E7 Am E7 Am E7 Am E7 Am A7 Dm G7 C F E7 Am and the centers of the melody are correspondingly for each of the above chords the  E E E E E  B A B A A F G E F D A . The melody-moves consist of 10 notes ,the first 9 belong to the first chord and the last 10th to the next. All the moves are on the chord transitions of the form X->(x+1) in the symbolism of the cycle of 24 chords (see post  34). E.g. E7->Am, or Am->E7, or A7->Dm, or G7->C. An exceptions is the transition F->E7.  The notes that belong to the chord for each of these moves are 6 from the 9, that is 2/3 of the notes. They achieve it ,as we said , by repeating notes of the chord. And even in the transition F->E7 the notes hat do not belong to the chord F, while F sounds , do belong to the next chord E7 and so they prepare the ear for the next chord. The melody has all the 4 harmonic speeds (see post 68).  They start (ignoring the repeating notes) from the root A of Am and end to the root E of E7,they go back and forth, then from the root A of Am go to the dominant B of E7 and back to the root A of Am. Then they repeat. Then from the root A of Am which is also of A7, they go to the middle note F of Dm. Then from the root G of G7 to the middle E of C. Then from the root of F to the chord F to the 4th note (7th) D of E7, and close back to the root A of Am.  Starting from the root of X7 and ending in the middle (2nd note)  or dominant (3rd note) of (x+1), (e.g. starting at a of A7 and ending at f of Dm) creates a tension, which resolves at the end of the cycle of 16 moves by ending at the root of minor chord (x+1) (here at a of Am).

Here is the result.

https://www.youtube.com/watch?v=CEPsAIqnVao

Now going back to the chord-melody improvisation. In such chord-transition melodic moves, a very good way to alternate chords and melody, is by playing the chord exactly at the notes of the simplicial submelody, that is exactly at the start and end notes of the melodic move. The chord played at the starting note of the melodic move, covers in advance the melody that will be played during the melodic move, while the chord played at the ending note of the melodic move will cover this note only. In general this means playing the chord at the start of its duration only , while during its duration, if there is a parallel melody it is played the melody. 

How to play slow soling on any scale across the fretboard, by knowing only chord-shapes and not scales-shapes!

How to play slow soling on any scale across the fretboard, by knowing only chord-shapes and not scales-shapes!

Here we are taking mainly not for the 6-string guitar but for 4-string instruments that , inherit the tuning from the higher 4-strings of a 6-strong guitar either with the exact frequencies (D,G,B,E) , or only isomorphic-ally (G,C.E,A), (D,F,A,D) etc like Greek 4-double string Bouzouki, Ukulele, baritone ukulele, ukulele-charango etc (For such instrument see  post 67).

Such instrument do not only give exact voicing of the 4-notes chords (no repeating notes) , but this also means that the arpeggios of the major or minor or also with 6th or 7th such chords, are identical with the chord-shape! This has the advantage that we do not need to learn scale-shapes across the fretboard, because as we shall see the scale-shape on all of the fretboard can be obtained as a simple sequence of  (usually only) 3 basic chords of the scale!

Le us take the example of the diatonic scale (e.g. D major) . Let us denote the 7 notes of such a major -mode scale by I, II, III, IV, V, VI, VII, I(=VIII). For the D major-mode scale it wold be 

D4, E4, F#4, G4, A4 , B4 C#5, D5

Now it is known that the chords, with roots on the notes of the scale are also denoted by latin numerals, capital if major and small if minor

 I, ii, iii, IV, V, vi, vii(dim), I(=VIII)

And by substituting the minor chords with their upper or lower major relative chords we get the chord progression

I, IV, I, IV, V, IV, V, I or for the D major-mode on particular the chord progression

D4, G4, D4, G4, A4 , G4 A4, D5  (=1,4,1,4,5,4,5,1)

In the symbols for guitar chords as in post 23 that pin down the place in the fretboard and the shape of the chord, the chord progression is the next:

D->(3E)G->(5A)D->(5D)G->(5E)A->(10A)G->(8D)A->(12D)D

Notice that

D, and G or (3E)G is at the 1st neighborhood o the fretboard (see posts 5, 13)

5A)D->(5D)G->(5E)A are at the 2nd neighborhood

and (10A)G->(8D)A->(12D)D are at the 3d and 4th neighborhood (see posts 5, 13).

When improvising, by listening to the 3 chords D, G, A, the sounds of the notes of the D major scale are created in the subconscious, and then by playing single notes based on he shapes of the above sequence of chords,  the full D major scale is deployed under our fingers!

It is clear that the notes of these chords do cover the scale and in fact contain no more notes than those of the scale (we always talk only for the higher 4 strings of the 6-string guitar and similar 4-string instruments, see post 67) .

So the way to play the scale, in slow soloing, would be to play the shapes of the above chords in that order, but not strumming the guitar, and only playing one note  of the chord shape , and not the rest of the notes of the chord. (The rest might be used in a enrichment of the melody). This chord progression not doubt will give all the notes of the D major-mode  scale.
We are saying slow soloing because obviously , the speed with which we change chord-shapes on the fretboard, is slower than the speed we may play single notes of scale.  But fast soloing is not always the beautiful or required. Slow soloing is more soulful and melodic, giving the opportunity for intermediate chord sounds too.
Notice that this requires that we know all the variations of an open chord-shape as non-open chord shale across the fretboard. But this is also easy and has been discussed together with the concept of 3 basic neighborhoods of the fretboard e.g. in post 3 and post 13.

Now all other 7 modes of the diatonic scale have again as chord progression to play them a cyclic permutation of the above chord progression.

Similarly other scales . e.g. like harmonic minor, or Hungarian minor (=Harmonic double minor) have similar alternating sequence of  usually 3 basic chords that create the scale-shape across the fret-board. So the above technique still applies.