An Introdution to Music Theory

19 Nov An Introdution to Music Theory

I am sure you will already be aware that songs are played in a particular key signature and using a given scale within that key. In this article I will try to explain, with examples, just what this means.

Scales

The Pentatonic Scale

There are many types of scales but the majority of blues and blues based rock is played with the minor and major pentatonic shapes (with a few variations such as the flat 5^th or blue note). Pentatonic being a five note scale.

This is the scale of A pentatonic minor with the root (A) on the 6^th string.

Here is the same scale with a change of position that will allow you to go higher up the neck i.e. “the extension box”.

This is a different version of A minor pentatonic starting with the root on the 5^th string. This is an octave higher than the previous one, as indicated by the 8va above the stave.

The A Major Pentatonic scale with the root on the 6^th string

And again the A Major pentatonic with extension box.

This is the same scale starting with the root note on the 5^th string, again the 8va indicating played one octave higher than written.

The A Natural minor scale. There are seven notes in contrast to the pentatonic’s five,

If you compare them – A B C D E F G with A C D E G you can see that the pentatonic minor is an abbreviated version. The Pentatonic minor scale has no 2^nd and no 6^th note.

A Natural minor starting with the root on the 5^th string.

This is the A Major scale with the root note on the 6^th string. The seven notes are:

A B C# D E F# G#, in comparison with the pentatonic’s five A B C# E F#, so again it can be seen that the pentatonic is an abbreviated scale. The Pentatonic Major scale has no 4^th and no 7^th note.

and A Major one octave higher with the root note on the 5^th string.

Essentially all of these scales are movable because they contain no open strings. All of the above examples are in the key of A minor or A Major because they start with the A note on either the 5^th or 6^th string. To change key simply move the scale to the root note required and as long as the same shape is played then the notes will be correct for the key.

For example, if the above scale is moved down to the D note at the 5^th fret of the fifth string and the same shape is played then the notes D E F# G A B C # D will be played , i.e. the D Major scale.

If the very first example (A pentatonic minor with the root A on the 6^th string) is moved up to say the 12^th fret E note then the scale is E minor pentatonic E G A B D.

Relative keys

If you compare the A minor scale A B C D E F G A with the C Major scale C D E F G A B C

you will see that they have the same notes, just starting from a different position.

Therefore these two scales are referred to as being relatives and this is true of every key.

Major Key                  C      Db      D       Eb      E       F       F#      Gb      G      Ab    A       Bb     B

Relative Minor         Am   Bbm   Bm   Cm   C#m   Dm   D#m  Ebm   Em   Fm  F#m   Gm   G#m

On the guitar to find a relative minor key simply move down (flatten) by three frets.

i.e. A Major to F# minor, F# is three frets lower than A,

C Major to A minor,  A is three frets lower than C.

If there are any questions, don’t be afraid to ask. Failing that there is always SKYPE. I hope this will solve the ‘mystery’ of where to play on the fretboard for someone.