As you may have noticed by now, certain chords seem to appear again and again when playing in particular keys. For example:

· C Major; F, G, Am
· G Major; C, D, Em
· D Major; A, G, Bm

Sound familiar? Let's take a look at how these chords are inter-linked.

The Major Scale

Don't start panicking, it's not as scary as it sounds! To understand chord links, let's look at an example. We'll start with C Major, as it has no sharps or flats and makes life easier!

Diatonic Interval   T   T   S   T   T   T   S
Note or Chord     C   D   E   F   G   A   B   C

Above is the C major scale, with the root of the scale in red, from which the scale gets it's name, and the tonal intervals above i.e. D is a Tone (whole note) above C, F is a Semi tone (half a note) above E. if this confuses you, try looking at a keyboard. Think of the black notes as Semi tones!

Diatonic Intervals

How does the above scale help us understand chordal intervals? For every note in the scale, there is a chord of the same name.

Diatonics involves splitting all of the chords in a major scale into three groups

· Tonic- start, or place of rest
· Sub-dominant- passing between tonic and dominant
· Dominant- resolving, or finishing

Let's give our chords some numbers:

  Tone Tone Semitone Tone Tone Tone Semitone
 C    D    E        F    G    A    B        C   
 I   I I  III      I V   V   V I  VII       I
Maj  Min  Min      Maj  Maj  Min  Dim      Maj

· Tonic - I Also III, VI
· Sub-dominant - IV Also II
· Dominant - V Also VII

Looking at our example above, we can see how chords are linked to whichever key or scale you are in. Try a tonic, sub-dominant and dominant in that order. i.e.

I  IV  V    III  IV  V    VI  IV  V    I  IV  III
C  F   G    Em   F   G    Am  F   G    C  F   Em

You may find it reminds you of several songs!

Confused? Ok, let's try it with a different key. e.g. D

So, our scale would be:

  Tone Tone   Semitone  Tone Tone  Tone  Semitone
 D    E    F#         G     A    B     C#        D
 I   I I   III       I V    V   V I    VII       I
Maj  Min   Min       Maj   Maj  Min    Dim      Maj

Ok, in the key of D, our examples above would look like this:

I  IV  V     III  IV  V     VI  IV  V     I  IV  III
D  G   A     F#m  G   A     Bm  G   A     D  G   F#m

Ok, so it might not look like Stairway To Heaven, but let's mix and match a little:

I  II  V  I  IV  V  IV  I  VI IV  V  I
D  Em  A  D  G   A  G   D  Bm G   A  D