Diatonic Scales
Diatonic scales comprise of a series of consecutive half steps and whole steps in alphabetical sequence that uses all 7 note names. The pattern of steps determines the type of scale. The pattern is consistent from octave to octave. The two most commonly used diatonic scales are: major and minor.

Major Scale
The major scale is a series of eight pitches where the 8th note is the same as the 1st note but an octave higher. This scale comprises of half steps between steps 3 and 4 and half steps between 7 and 8. All other steps are whole steps.

A major scale does not need to begin on the same note as the scale eg; the C major scale does not need to start and end on C. The A major scale can start on any note within the scale as long as the major scale pattern is maintained:

W W H W W W H

Note: Major scales that begin and end on a note other than the scale name are known as modes.

Minor Scale

The minor scale is a series of eight pitches – the 8th notes is the same as the first but an octave higher.

There are three forms of minor scale:- natural, harmonic and melodic.

Natural Minor Scale
The scale pattern for the natural minor scale is as follows: W H W W H W W

Harmonic Minor Scale
This is identical the the natural minor scale with the exception that the seventh step of the scale is raised. This creates a 1½ step gap (minor 3 rd interval) between the 6th and 7th degrees: W H W W H m3 H

Melodic Minor Scale
This scale uses a different interval pattern when ascending and descending. The ascending pattern is identical to the natural minor but with raised 6 th and 7 th degrees: W H W W W W H

The descending pattern of the melodic minor scale is the same as that of the natural minor.

Scale degree names

1. Tonic - first degree, determines the key/tonality
2. Supertonic – second degree, “super” = above
3. Mediant – third degree, midway between tonic and dominant
4. Subdominant – fourth degree, sub meaning ‘below’
5. Dominant - fifth degree, second only to tonic in terms of importance
6. Submediant – 6 th degree, midway between tonic and subdominant
7. Leading tone – seventh degree, leads back to tonic.

The terms tonic, subdominant and dominant are commonly used in music. Terms such as supertonic, mediant and sub mediant are more commonly referred to nowadays by their numerical relationship to the scale eg: II chord, III chord or VI chord.

Whole Tone Scales
There are only two possible whole tone scales: C and C#. This scale comprises of 6 notes separated by whole step intervals.

Pentatonic Scales
Pentatonic scales consist of 5 notes (pent = 5). There are two types of pentatonic scale – tonal and semi-tonal.

Tonal Pentatonic Scales
These scales do not contain half steps, only intervals of a whole step or longer.

Major – W W m3 W m3

Minor – m3 W W m3 W

Semitonal Pentatonic scales
This scale contains half step intervals.

Major - m3 H W m3 H

Minor – m3 W m3 H W

Blues Scale
This is one of the more popular scales, especially with the major third and flat fifth. The interval pattern is as follows:

M3 H H H H m3 W

Keys

A song that uses the same scale of notes above a certain tonic is referred to as being in the key of the particular tonic. So for a song that generally uses notes from the C major scale is said to be in the key of C major.

Key Signatures
Apart from the keys C major and A minor, all keys must use one or more accidentals (sharps and flats). These are placed at the beginning of each staff to avoid having to place them against each note where an accidental would be used. The music is therefore less cluttered and much easier to read.

Major Keys - Flat Keys

C (no flats)
C D E F G A B C

F Major (one flat)
F G A Bb C D E F

Bb Major (two Flats)
Bb C D Eb F G A Bb

Eb Major (three flats)
Eb F G Ab Bb C D Eb

Ab Major (four flats)
Ab Bb C Db Eb F G Ab

Db Major (five flats)
Db Eb F Gb Ab Bb C Db

Major Keys - Sharp Keys

C (no sharps)
C D E F G A B C

G Major (one sharp)
G A B C D E F# G

D Major (two sharps)
D E F# G A B C# D

A Major (three sharps)
A B C# D E F# G# A

E Major (four sharps)
E F# G# A B C# D# E

B Major (five sharps)
B C# D# E F# G# A# B

Minor Keys

A minor key has the same key signature as the major key that lies a minor third above it. Eg: A minor has the same key signature as C major.

Relative, Parallel and Enharmonic Keys

Relative Keys
A major and minor key that have the same key signature are called relative keys. Eg; A minor is the relative minor key of C major and C major is the relative major key of A minor:

Parallel Keys
A major key and minor key that share the same letter are called parallel keys eg; B major is the parallel key of G minor.

Enharmonic Keys
This is where two keys sound the same but are referred to by different names. There are three pairs of enharmonic major keys and three pairs of enharmonic minor keys:

Circle of Fifths

All keys and their enharmonic relationships can be summarised using what is known as the circle of fifths. This is a circle that shows the twelve keys are arranged in a fashion where the number of sharps in the signature increases as you go clockwise. As you go anti-clockwise, the number of flats increases.

Intervals

An internval is the distance between two specific pitches measured by the number of half steps/whole steps it contains eg C to G is a fifth because it encompasses five letter names: C D E F G.

Melodic intervals occur sequentially. Harmonic intervals occur simultaneously.

Intervals can be perfect, major, minor, augmented or diminished. The interval quality can be determined by the following.

Interval Quality
If you look at a major scale of C using the lower pitch as the root (tonic). If the upper pitch is one of the notes of the major scale and is the same note, fourth, fifth or an octave higher than the tonic, this is called perfect (P)

If the upper pitch is a second, third, sixth or seventh above the tonic, the interval is called major (M).

• If a major interval is reduced by half a step, this is called a minor.
• A major or perfect interval that is increased by a half step is called augmented (aug).
• A minor or perfect interval decreased by a half step is called diminished (dim).

Compound Intervals
This is an interval that spans greater than one octave. A simple interval is are equal to or less than an octave in distance.

Chords

A chord is a simultaneous sounding of three or more pitches. Traditionally, in harmony, chords are constructed on a system of superimposed thirds.

Triads
A triad is basically a three note chord. The chord is made up of the first, third and fifth degrees of a scale. The lowest note sounded in the chord is in the ‘root position’ – the root of the chord.

Chord Quality
Depending on how they are constructed, chords may be any of the following:

Major, minor, augmented or diminished.

Major triads - a major triad consists of the first, third, and fifth degree of the scale

Extended Chords

These are defined as chords with four or more notes. They are named according to the highest interval:

Seventh Chord – adds the seventh degree of the scale above the basic triad.

Ninth Chord – add the ninth degree above the basic triad along with the seventh.

Eleventh Chord – adds the eleventh degree above the basic triad along with the seventh. The ninth degree can be included or omitted for it to still be considered an eleventh chord.

Thirteenth Chord – adds the thirteenth degree above the basic triad along with the seventh. Still referred to as a thirteenth chord even if the ninth and eleventh degree are not present.

Dominant Chords
A major triad built on the fifth degree of the scale with a minor seventh tone added is referred to as a dominant seventh chord.

A dominant seven chord with the addition of the ninth is called a dominant nine chord.

Chord Inversions

 A chord is in the root position as long as the root note is the lowest of all the notes within any given chord.

If any other note in the chord, other than the root is lowest, the chord is considered to be inverted. See the following definitions:

First Inversion Chord – if the third degree of the chord is on the bottom.

Second Inversion Chord – if the fifth degree of the chord is on the bottom.

Note: Chord with extensions above the triad have additional inversions depending on the number of notes in the chord.