Chromatic Scale
This scale comprises all 12 notes in an octave. The notes are arranged in consecutive order, either ascending or descending in half steps. Generally, sharps are used when ascending & flats are used when descending.
Diatonic Scales
Diatonic scales comprise of a series of consecutive half steps & 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 & 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 & 4 & half steps between 7 & 8. All other steps are whole. Major scales that begin & end on a note other than the scale name are known as modes. The scale pattern is: W W H W W W H
Natural Minor Scale
The scale pattern is: W H W W H W W
Harmonic Minor Scale
This is identical to the natural minor scale with the exception that the seventh step of the scale is raised. This creates a 1½ step gap (minor 3rd interval) between the 6th & 7th degrees: W H W W H m3 H
Melodic Minor Scale
This scale uses a different interval pattern when ascending & descending. The ascending pattern is identical to the natural minor but with raised 6th & 7th 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 degrees
- Tonic, 1st degree - determines the key/tonality
- Supertonic, 2nd degree - “super” = above
- Mediant, 3rd degree - midway between tonic & dominant
- Subdominant, 4th degree - sub meaning ‘below’
- Dominant, 5th degree - second only to tonic in terms of importance
- Submediant, 6th degree - midway between tonic & subdominant
- Leading tone, 7th degree - leads back to tonic.
Whole Tone Scales
There are only two possible whole tone scales: C & C#. This scale comprises of 6 notes separated by whole step intervals.
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 & flat fifth.
The interval pattern is:
M3 H H H H m3 W
Key Signatures
A song that uses the same scale of notes above a certain tonic is referred to as being in the key of that tonic. Apart from the keys C major & A minor, all keys must use one or more accidentals (sharps & 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 & much easier to read.
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
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
Minor Keys
A minor key has the same key signature as the major key that lies a minor third above it.A minor has the same key signature as C major.
Parallel Keys
A major key & minor key that share the same letter are called parallel keys. B major is the parallel key of B minor. In music, the parallel minor or tonic minor of a particular major key is the minor key with the same tonic; similarly the parallel major has the same tonic as the minor key. For example, G major & G minor have different modes but both have the same tonic, G; so we say that G minor is the parallel minor of G major.
To the Western ear, the switch from a major key to its parallel minor sounds like a fairly simplistic “saddening” of the mood (while the opposite sounds like a “brightening”). This change is quite distinct from a switch to the relative minor.
Flats always appear in the order B-E-A-D-G-C-F. Sharps always appear in the order F-C-G-D-A-E-B. For example, if there are 3 flats in the key signature, those flats would be B, E, & A. If there are 2 sharps in the key signature, they would be F & C. To find the parallel minor of a key, add 3 flats to the key signature. For example, F major has 1 flat (B). Adding 3 flats would yield 4 flats, meaning F minor consists of B, E, A, & D flat. B major has 5 sharps (F, C, G, D, A). To find B minor, add 3 flats. Since flats cancel out sharps, one is left with 2 sharps (F & C). To find the parallel major, add 3 sharps. E minor to E major: E minor has 1 sharp (F). Add 3 to get 4 sharps (F, C, G, D). F minor to F major: F minor has 4 flats (B, E, A, D). Add 3 sharps to get 1 flat (B).
Relative Keys
A major & minor key that have the same key signature are called relative keys. A minor is the relative minor key of C major & C major is the relative major key of A minor:
Major/Relative Minor
G/E
D/B
A/f#
E/c#
B/g#
F#/d#
C#/a#
Major/Relative Minor
C/A
F/D
Bb/G
Eb/C
Ab/F
Db/Bb
Gb/Eb
Cb/Ab
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 & three pairs of enharmonic minor keys:
Major
C#/Db
F#/Gb
B/Cb
Minor
Bb/A#
Eb/D#
Ab/G#
Circle of Fifths
All keys & their enharmonic relationships are summarized using the Circle of Fifths. 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 interval is the distance between two specific pitches measured by the number of half steps/whole steps it contains. 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.
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 & 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 & 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, & fifth degree of the scale
Minor triads - these are the first, minor third, & fifth degree of the scale
Diminished - these chords consist of the first, minor third, flat fifth, & double flat seventh degree of the scale. Note that double flat seventh is the same note as the sixth, but by convention it is usually written as double flat seventh!
Augmented - these are the first, third, & sharp fifth 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 & 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 inverted.
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.
Chord Type/Formula
Major Triad = 1, 3, 5 of major scale
Minor Triad = 1, b3, 5
Augmented Triad = 1, 3, #5
Diminished Triad = 1, b3, b5
Sus2 = 1, 2, 5
Sus4 = 1, 4, 5
5th = 1, 5
6th = 1, 3, 5, 6
Minor 6th = 1, b3, 5, 6
Minor #6th = 1, b3, 5, #6
Major 7th = 1, 3, 5, 7
Minor 7th = 1, b3, 5, b7
7th (dominant) = 1, 3, 5, b7
Diminished 7th = 1, b3, b5, 6
7sus2 = 1, 2, 5, b7
7sus4 = 1, 4, 5, b7
9th = 1, 3, 5, b7, 9
Minor 9th = 1, b3, 5, b7, 9
Major 9th = 1, 3, 5, 7, 9
6/9 = 1, 3, 5, 6, 9
11th = 1, 3, 5, b7, 9, 11
13th = 1, 3, 5, b7, 9, 13
Or more simply:
Chord Type/Easy Formula
Major Triad = 1+3+5 of major scale
Minor Triad = 1+b3+5
Diminished Triad = 1+b3+b5
Augmented Triad = 1+3+#5
Major Seventh = 1+3+5+7
Dominant Seventh = 1+3+5+b7
Diminished Seventh = 1+b3+b5+6
Minor Seventh = 1+b3+5+b7
I’ll need to read that post several more times before I completely understand it, but I really appreciate that. Thanks! 
