Гитарное искусство

 

 

 

 

 

 

 

 

 

 

СHAPTER 1. Method of double steps

The Lydian and Locrian modes are based on a one-direction sequence of fifths.

F Lydian:   F –> С –> G –> D –> A –> E –> B

B Locrian:  F <– С <– G <– D <– A <– E <– B

Other modes are built using both directions of the circle of fifths. The Dorian mode is built by making 3 steps in both directions.

D Dorian:

F < – С <– G <– D –> A –> E –> B

We could get the same result by making three consecutive steps of one fifth up and one fifth down. These are three double steps — three steps extending the sequence of fifths in both directions. Two double steps give pentatonic C, D, E, G, A.

The fourth double step yields F# and B♭. With this notes instead of F and B we have D melodic major and G melodic minor.

The next step up gives the note C# and D harmonic major, while a step down would give us E♭ and the Phrygian dominant mode of G harmonic minor.

Both these steps (notes C# and E♭ instead of C and E) give the double harmonic major scale on D and double harmonic minor scale on G.

All these scales feature symmetry around the center D. The scales obtained by adding one fifth up or down to the chain of fifths are the exception: they are symmetrical to each other (the ascending pattern of intervals of one repeats the descending pattern of the other). For example, the harmonic major is symmetrical to the Phrygian dominant mode of the harmonic minor.

Each scale has a mode for each of its individual scale degrees.

This method shows the emergence of scales and modes in the process of extending the sequence of fifths.

 

СHAPTER 2. Method of double steps (details)

So we have:

  1. D – tonic
  2. D, A, G – tonic, dominant and subdominant
  3. D, A, G, E, C – pentatonic scale
  4. Next two notes (F and B) yield a seven-note diatonic scale.
  5. Then in order to produce 7-note scales we will use alterations instead of adding new notes. We will get melodic, harmonic and double harmonic scales.
  6. Then the next alterations will yield the six-tone scale D, E♭, F#, G#, B♭, C#.
  7. Next double step yields D# and D♭ instead of D and yield pentatonic scale G#, B♭, C#, E♭, F# – five black keys of the piano keyboard. This new pentatonic scale and the first pentatonic scale are a tritone apart.

The order of the alterations is the reversed order of adding new notes.

Tonic, dominant and subdominant were the first notes that appeared in this process and the last notes that were altered. This stability illustrates their meaning in the key.

The notes F and B were the last notes that appeared in the process of adding new notes and immediately were altered. They are the most unstable notes in D Dorian. In blues, for example, D Dorian with F may sound over D Mixolydian with F#.

СHAPTER 3. Pentatonic vs diatonic

The pentatonic C D E G A is the stable nucleus of all seven modes that do not have sharps and flats.

This nucleus does not contain F and B. Therefore, Lydian and Locrian are not so common. Only C Ionian and A Aeolian have their tonic triads, which can be found in the nucleus. This may be one of the reasons why we usually use only two pentatonics and two keys: major and minor.

The nucleus does not have the IV of C Ionian. This is why the subdominant, dominant and tonic of C Ionian often become IIm - V - I.

So Lydian mode can be considered a form (inversion) of Dorian mode (F Lydian is used where D Dorian can be used).

In the same way Locrian mode can be played instead of Mixolydian: the Вm-5 chord is a part of the G7 chord and they can be used interchangeably. Вm-5 or G7 with В in the bass sounds good when the G note is in the melody.


© victorilivanov