Numerical Analysis of Chords

How to figure out chords on the guitar. (Part Two)

Continuing from the "Part One", let's take a look at the list of structures needed for "Four note" chords.

The “flatted 6th” (b6th) chord is in the exact same position as the “sharp 5th” (V+). Substitute one with the other to build the structure of the chord.

b6th = I - III - V - vi

Minor b6th = I - iii - V - vi

Major 6 = I - III - V - VI

Minor 6th = I - iii - V - VI

Diminished 7th = I - iii - v° - bvii <(double-flatted dominant 7th)

Dominant 7th - I - III - V - vii

Minor 7th = I - iii - V - vii

7th sus. 2nd = I - II - V - vii

7th sus. (4th) = I - IV - V - vii

7th flat 5th = I - III - v° - vii

Half-Diminished (minor 7th-flat 5th) = I - iii - v° - vii

Augmented 7th = I - III - #V - vii

Major 7th = I - III - V - VII

Major-minor 7th = I - iii - V - VII

Major 7th-sus. 2nd = I - II - V - VII

Major 7th-sus. (4th) = I - IV - V - VII

Major 7th-flat 5th = I - III - v° - VII

Major 7th diminished = I - iii - v° - VII

Major 7th-augmented = I - III - #V - VII

Major-minor 7th-augmented = I - iii - #V - VII

How many of these types of chords you will use in everyday practicality is debatable, however, they do exist mathematically. Many of these “strange structures” that are less-pleasing to the ears are considered "transitionary". In other words, they need to be placed in context with the chord structure of the song to make harmonic sense.

The next section will include a list of "Five note" chord structures used in extension chords. They will include variations of 9th's, 11th's and 13th's. 

That article will be posted in the upcoming "Part Three" of this series.