Jimmy's Chord Theory TOC                                          Lesson 5


"Wilson, STOP! my head is exploding. I don't

think I have anymore room in my head to put all this

information. What you're telling me is that I must

keep 12 major scales, 12 minor scales, 12 diminished

scales, and 12 augmented scales in my head at all

times just to play a little jazz?" I said wearily.


he reminded me, as well as the bus driver.

We started moving again, confirming my suspicion

that perhaps the driver had been asleep. Take the

bus and leave the driving to a total stranger.

"Why three and four," I queried hoarsely.

"Let's look at the NINE TONE SCALE and start on B."

B C# D E F G G# A# B

1 2 b3 4 b5 b6 bb7 7 8

"Now the chord."

B D F G#

1 b3 b5 bb7

"Transpose the chord one semitone up."

C D# F# A

1 b3 b5 bb7


C# E G A#

1 b3 b5 bb7


D F G# B

1 b3 b5 bb7

"It's beginning to repeat itself," I remarked.

B, D, F and G# diminished chords all have the

same notes. They must use the same scale as well.

"You got it."

"And the four augmented chords must be

C, E & G#;

C#, F & A;

D, F# & A#;

AND D#, G & B.


A SEVENTH CHORD is expected to be a

Dominant Major chord unless specified MINOR SEVENTH;

G SEVENTH for example is written G7,

G minor seventh is written Gm7 or G-7.

In either case the 7th is always a

FLATTED 7th,    implied, but never written as (b7th).


The only time a NATURAL 7th occurs is in a


written GMaj 7,

or a G followed by a small triangle symbol: G ^ 7



double flatted seventh, bb7, (flatted twice it is the same as a  6th),

otherwise a b7 makes it a HALF DIMINISHED chord.

In either case they both

contain the minor or flatted third and the flatted fifth.

DIMINISHED     B D F Ab B      B dim

1 b3 b5 bb7

°   =  Symbol for Diminished

HALF DIMINISHED    B D F A B 7      B dim 7th

1 b3 b5 b7


A HALF DIMINISHED chord is also called a


B D F A     written  Bm7 b5

1 b3 b5 b7


An AUGMENTED CHORD is a major chord with a

raised or sharped fifth.

C E G# C,       written  C aug   or   C+

1 3 #5

And when the flatted 7th is added to an AUGMENTED CHORD

C E G# Bb,      written   C aug 7   or   C+7  

1 3 #5 b7


Lower the fifth of the Augmented Chord and it becomes C7

C E G Bb

1 3 5 b7

Did you know that C7 is not in the key of C,

but is becoming F.  The key of F or F scale has one flat, Bb.


C7 is becoming or moving toward F

F7 is becoming or moving toward Bb

Bb7 is becoming or moving toward Eb

Eb7 :  Ab

Ab7 :   Db

Db7  :  Gb

Gb7  :  B

B7  :  E

E7  :  A

A7  :  D

D7  :  G

G7,  guess what,  C


This is called the CIRCLE OF FOURTHS;

played backwards, the CIRCLE OF FIFTHS.

The interval from C to F is 4 major scale tones

C D E F  from C to F

the 1 2 3 4 interval is a fourth

The interval from C to G is 5 major scale tones

C D E F G  from C to G

the 1 2 3 4 5 interval is a fifth


Analyze these blues chords for intervals:

C F7 C

1 4 5

What is confusing is that from C to F is four steps

and from F back to C is five steps.

C D E F      F G A Bb C

1 2 3 4          1 2 3 4 5

This is what is called progression, moving forward.

"We really are, there's the New York skyline,

but it's chopped off at the 25th floor." I commented.

We had been talking and listening for six hours, trying

to make sense of music theory and I had come to one

very important conclusion that would allow me to

calculate chords or decipher them with ease.


"Wilson, tell me if this is true," I asked.

I figured out that a major chord is always the

first, third and fifth note of the scale.

1 3 5


C# F G#

D F# A

Eb G Bb

E G# B


F# A# C#


Ab C Eb

A C# E

Bb D F

B D# F#

I also know that based on a major scale of  1 2 3 4 5 6 7 8

I can calculate any kind of chord by formula. i.e.

since major is 1 3 5 then

minor is 1 b3 5,  written m or -

diminished is 1 b3 b5,  written o or dim

augmented is 1 3 #5,  written + or aug


major seventh is 1 3 5 7,  written  Maj7 or Δ7

minor seventh is 1 b3 5 b7,  written  m7 or -7

and dominant seventh is 1 3 5 b7,  written  7.


The full diminished is 1 b3 b5 bb7,  written   °

half diminished is 1 b3 b5,  written  b7 or  °7

or minor seven flat five,  written  m7b5    or  -7b5

augmented seventh is 1 3 #5 b7,  written  +7 or   aug7



ŠJimmy Warner Design, 2016