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Showing posts with label 75. The correlation of the accumulative pitch shift of melodic themes with the pitch shift of their chords in the 12-cycle of chords by intervals of 4th. Show all posts
Showing posts with label 75. The correlation of the accumulative pitch shift of melodic themes with the pitch shift of their chords in the 12-cycle of chords by intervals of 4th. Show all posts

Sunday, February 19, 2017

75. The correlation of the accumulative pitch shift of melodic themes with the pitch shift of their chords in the 12-cycle of chords by intervals of 4th

(The post has not been written completely yet)

Most easy to sing songs use the triads chords of the diatonic scale, either the major triad , (V, I, IV) or the relatives minor triad   (iii, vi, ii). Now these triads are successive chords in the 12-cycle of chords by intervals of pure 4ths (5 semitones) (See e.g. post 32, qnd 34 ).

But as we have said the best fit of melody and chords is one that there is a correlation between the "emotional story" of the themes ofthe melody and the "emotional story" of the parallel chord progression (see e.g. post 27).

The simplest such correlation is that, when utilizing e.g. the triad (V, I, IV) for the song, the theme that is parallel to a  chord transition e.g. I->IV is ascending in total accumulation  in pitch (easily seen in the simplicial sub-melody), while while going to V (either from IV, or from I) is descending. In other words also the transition resolutions  V->I, I->IV are ascending or descending, while the transitions that are inverse of the resolution,  I->V, IV->I are descending or ascending respectively, but always with a fixed correlation during the song. Thus cycling in the triad is essentially alternating going up and going down in the total accumulated pitch of the melodic themes which also creates a feeling of balance and easy to sing concept. The major triad is also partially or totally substituted by the minor triad (iii, vi, ii), but always with the same pitch correlation rule, before we return back to the major triad again. We are always considering the golden rule: At least  2/3 of the notes (as duration) as notes of the chord and at most 1/3 of the notes (as duration) as notes outside the chord. And at least 2/3 of the chords (as duration) being major chords, and at most 1/3 of the chords (as duration) as minor chords.
This correlation seems to be the strongest among the "pitch emotional story" of the melodic themes and the "pitch emotional story" of the chord progression. By utilizing the chord transition relation of relative chords, and substituting major chords on the 12-cycle of chords by  4ths, with one of their relative minor chords , the correlation is inherited in the minor chords, while now there appear transitions of complementary chords, (e.g. I->IV->I , may become I->ii->I). But still the pitch-shift  correlation is that of the original chords in the 12-cycle rather than that of complementary chords.

A natural way to define the pitch dynamics of the melodic themes, and  the "emotional story" of the melodic themes is directly from the speaking language, when we shape phrases and speak them. There is a natural shaping also of the pitch dynamics that comes from the meaning of the words, or not exactly from the meaning of the words but from the intended emotional background of our speaking. It can be soothing agitating, reassuring, irritating, angry, calming , waving, falling in itch ,or increasing in pitch etc. The common way of composition starts from the words, and their speaking pitch dynamics, it goes to the melody, melodic themes  pitch dynamics and then to the harmony. But in this book we prefer the harmonic method. The harmonic method does not necessarily restrict the composer, to define the pitch dynamics of the melodic themes from the speaking language dimension, as any such pitch dynamic can be derived also from pre-defined chord progressions, if we chose properly the inversions and scales of the chords of the chord-progression.

By utilizing this method of relative chords , where we include the 3rd relative relation (chords of the same root one major the other minor e.g. A->Am) we may have scale modulations where no # or b shift occurs in the chords of a single scale, For such modulations ,it is still possible to reduce virtually the chords only to the major triad of a single diatonic scale , and check the correlation of of pitch shifts, of the melodic themes and chord transitions. This can be done with more complicated scale modulations , where locally in time we are still in a single diatonic scale (definable easily by an arc, in the 12-cycle of chords by 4ths)

To play and observe these correlations of melodic and chord shifts on the guitar see also the post 13 about the 3 neighborhoods of the guitar fret-board