This is a document in progress so stay tuned. This has helped a lot of my students to take the mystery out of applied music theory. It is of course relevant to all musical instruments. You do not need a 'chord dictionary' learn the basics and you can create them all.

1. 4
4
etc ...
A A Sharp B
!----------!
C
A B Flat B
!----------!
C
VII
Half Tone
B
VIII
C
E
!---------!
F F Sharp G G Sharp
E
!---------!
F G Flat G A Flat
Tone
V
Tone
G
VI
Tone
A
NOTE: Remember this: BC 'Before Christ' and EF 'Encourage Freedom'
C C Sharp D D Sharp
C D Flat D E Flat
THEMAJOR SCALEIN C MAJOR
Tone
III
Half Tone
E
IV
F
A A Sharp
!---------!
B
3
Please note - there is no sharps or flats between the notes of B and C or E and F (the green notes)
These enharmonic notes can be referred to as a sharp (#) or a flat (b) - e.g., A# is the same note as Bb
A B Flat B
!----------!
4
Tone
I
C
II
Note that the Chromatic Scale has no structure - just a stream of half tone notes. A Major scale takes those notes and creates a structure.
That structure is the intervals between the note which create TONE, TONE, HALF TONE, TONE, TONE, TONE, HALFTONE,
as can be seen below.
D
5
NOTE: Remember this: B & C is a half tone apart and E & F is a half tone apart - all the rest have enharmonics between them.
These are the notes that exist between most of the Natural Notes - called 'Enharmonic' or sharps and flats (the black notes on the piano)
E F G A B
B
A C D
ENHARMONIC EQUIVALENT NOTES - Together with the natural notes creates the 'Chromatic Scale' (each note being a half a tone apart)
D E F G
A B C
2
NATURAL NOTES
F
A
This creates a musical alphabet that starts with A and ends with G then repeats an octave higher (these are the white notes on the Piano)
B
E
G
C
ED
F
Notes on the stave - lines E G B D F and spaces are F A C E
Leo Crossfield
Begining to Understand Music Theory

2. G
So when we see a key signature of F# we know that the key is G.
Every major scale has what is called its 'relative minor' which is a scale based upon the 6th note of the major scale. In the
key of C this is A and in the key of Git is E. The relative minor scale starts on the 6th note and progresses through the
same notes as the major scale and ends on the 6th note and it also shares the same key signature as the parent major scale.
So for example:
We can see that the natural minor has a different structure to the major scale even though it is using the same notes, but more
importantly it has a different sound and feel due to the III note or third note of the scale interval being only one and a half tones
fromthe root or first of the scale whereas in the major scale the third note interval has two tones - the major scale third interval
is called a major third and the minor scale third interval is called a minor third. This scale also has b6 and b7 if we sharpen the
3rd, 6th and 7th of the scale we create an E Major scale (the key of E Major has a key signature of F#, C#, G# and D#).
So we sharpen the F to make it F sharp (F#) which moves the seventh note up one half tone thereby creating the correct major
scale structure for the Gmajor scale.
Rather than write every F note with a sharp we add a general sharp to the begining of the stave (just after the treble clef -
in red below). This means that every time the player encounters an F they must play it sharpened. This is called a 'Key Signature'.
E FC D
Between the VI and VII we have a half tone interval where we need to have a tone, and between the VII and VIII notes we
have a whole tone interval where we need to have a half tone. So the the natural structure does not create a major scale as
it did in the key of C. So we have to modify it by changing the F to an F#.
A BG
The natural notes of the C Major scale naturally formthe structure of the major scale. But when we use other keys we
have to alter some of the notes to force theminto the structure of the major scale.
Above I have used the natural notes to try and forma GMajor Scale - starting with Gand ending with Gand as we look at
the intervals between the notes we find that we have a problem- it doesn't formthe structure of a major scale.
OTHER MAJOR SCALES
VIII
VIII
VIII
VI Half Tone VII Tone
VI Tone
C
VII
D
Tone VIII
E
VI Tone
C#
VII
D#
Half ToneVIII
E
IV Tone V Tone
IV Tone
A
V
B
Half Tone
IV Tone
A
V
B
Tone
Tone II Tone III Half Tone
Tone II
F#
Half Tone III Tone
G
ToneI
E
II
F#
Tone III
G#
Half Tone
I
9
I
E
10
11
2
VI Half Tone VII ToneIV Tone V ToneTone II Tone III Half ToneI
8
THE MAJOR SCALE IN G MAJOR
VI Half Tone VII ToneIV Tone V ToneTone II Tone III Half ToneI
2
7
6

3. Using the C Major scale and the GMajor below as examples, all of these chords have a role to play however the simplest
tunes utilise the I, IVand Vchords.
It is worth noting that these are the only Major chords within the scale. All the rest are minor chords; they have a minor third.
The unusual one is the 7th chord which is called a diminished chord and has both a minor third and a flat or diminshed fifth.
The Vchord (fifth chord) has a specific function in a key - it's job is to take the tune back to the I chord (root chord). This
is called a 'cadence' and the V- I is a specific kind of cadence and the Vchord has a particularly strong pull to resolve to the
I chord. It more often than not has an additional b7th added to the it.
Example below is in the key of Gand of course the Vchord is a D or with the b7 it is called a V7 or D7. The additional note
is a C so the spelling of the chord is D, F#,A, C (1, 3, 5, b7).
A 'TRIAD' is a three note chord - which includes the First, Third and Fifth of the major or minor scale played at the same time.
Each of the chords above take their root fromeach note of the Major scale creating a sequence of chords, or a chordal scale
progression, and whether a chord is a Major or minor is determined by the interval between the root and the third of the triad.
3
Bdiminished
vii
CMajor
F#diminished
vii
GMajor
V
GMajor Aminor
vi
IV V
DMajor Eminor
vi
CHORDS IN A KEY
ii
Eminor
iii
FMajor
IV
Aminor
ii
Bminor
iii
CMajor
Three half tones
I
CMajor Dminor
15
I
GMajor
16
17
Four half tones
D, D#, E, FC, C#, D, D#, E
14
!----half tone---!
D minorCMajor
Both a Major and a Minor Triad have a Fifth so in practice - if you learn the major triad and flat the third you create a minor triad
One and a half half tones is called a Minor third
!--------------tone----------------!!--------tone---------!
Two whole tones is called a Major third
!--------tone---------!
D minor
13
C Major
Bdiminished CMajorFMajor GMajor AminorDminor EminorCMajor
HOW CHORDS (Triads) ARE CONSTRUCTED FROM THEMAJOR SCALE
12
Taking the I, III and Vof each note of the Major scale and stacking themon top of the root note gives us harmony.

4. We can also do this for the Gminor major seventh (GmM7) chord - fancy name but it is G, Bb, D, F# (1, b3, 5, 7).
We know that the major chords are contructed fromthe scale by taking the 1, 3 and 5 notes of the scale and for minor chords
1, b3 and 5 of the scale. We can also take other notes fromthe scale and add themto the basic triad. If we want a GMajor
seventh (GM7 or GMaj7) all we need do is add the natural seventh of the Gmajor scale (fromthe chords own scale which is G)
to the basic triad as we did for the Dominat seventh. So we have the basic Gtriad of G, B, D (1, 3, 5) and add the F# (natural 7th)
and we get G, B, D, F# = GMaj7. Likewise adding the sixth of the scale gives us a G6 - the spelling is G, B, D, E (1, 3, 5, 6).
If someone asked you to play Gm7b5 (Gminor seventh flat 5) - you would probably freak out. But using this theory it is not
difficult at all. First you play your basic Gmajor chord - G, B, D (1, 3, 5) then you flat the 3 = G, Bb, D to create a minor triad
then you flat the 5 and now have G, Bb, bD - then you need to add the seventh - the seventh is always a b7 fromthe chord's
own scale, otherwise it will be called a Maj7. So the key of Ghas a natural seventh of F# - we flat it and get F and add that to
the chord. We then have G, Bb, Db, F = Gm7b5.
First we need to understand incidentals in music theory. An incidental is a sharp or flat or natural sign which takes presedence
over the key signature. So using a natural sign on the Gdominant 7th above will tell the reader to ignore the F sharp in
the key signature for the specific bar. So although the F should be played as F# having a natural before it it will be played as F.
In essence flattening it. If there was no F# in the key signature we would have used the flat (b) to flatten it.
Of course this does mean that as players we do need to know how to finger our chords and which finger is holding which
degree of the scale. If I don't know where my third is I will not be able to flat it to make a minor chord.
MODIFYINGCHORDS
Many students learning stringed instruments learn their chords froma book. The problemthere are so many variations
that this becomes a major memory exercise when a little theory goes a long way in being able to construct your own chords.
This rule is true for all keys. In the key of C the Vchord is G. So we look to the key of Gand find that the Major 7th is F#
so we flat F# which gives us F and add that note to the Gmajor chord giving us a spelling of G, B, D, F (1, 3, 5, b7).
The seventh note of the V7 chord is taken fromVchord's own key. A natural seventh (known as the Major Seventh) in
in the key of D would be C#. The key of D has a key signature of F# and C# so the note C is a b7 in the key of D and
that is what is added to the D chord to create a D7 in the key of G.
When the b7th is added to the Vchord we call it a Dominant 7th or Dom7. Adding the b7 gives it an even stronger pull to
the root chord.
G6
G6
GMajor
vi vii
Eminor F#diminished
B C#
VIII
D
VI VII
Gdom7GminMajor7
Gmin7b5
GMajor7
21
22
23
4
Gdominant7GminMajor7GMajor7
20
iii IV V7
CMajor D Dom7
I ii
GMajor Aminor Bminor
19
F# G AD E
III IV VI II
18

5. 5
27
28
29
26
25
24

6. 6
33
34
35
32
31
30

7. 7
37
36