A chord is produced when three or more different notes are played together.
These combinations of notes produce various types of chord.
A chord can be built on any note.
The note on which a chord is built and from which the chord takes its name is called the ROOT NOTE.
For example, ‘G’ is the root note of the ‘Gm7’ chord and ‘E’ is the root note of the ‘E7’ chord.
To form a chord:
1) Refer to the major scale of the root note.
For a ‘C Major’ chord, refer to the ‘C’ major scale.
C D E F G A B C
2) Extend the scale so it goes up two octaves.
C D E F G A B C D E F G A B C
3) Then number each note.
4 ) Now we need the chord formula for the type of chord we are building.
The formula for a major chord is 1: 3 : 5
To build a ‘C’ major chord you need the 1st, 3rd and 5th notes of the ‘C’ major scale.
So, the notes of a ‘C’ major chord are C : E : G
The formula for a minor chord (m) is 1: b3 : 5
To build a ‘C’ minor (Cm) chord you need the 1st, b3rd and 5th notes of the ‘C’ major scale.
‘b3’ means flatten the third note (move it down in pitch by one semitone).
So, the notes of a Cm chord are C : Eb : G
Chord symbols are used as abbreviations for the full name of a chord and are used by musicians in chord progressions, like this one:
|| C | Fmaj7 | G7 | Am9 ||
MAJOR CHORD SYMBOLS
Three note major chords (triads) use the root note as the chord symbol.
For example, ‘G‘ is the symbol used for a ‘G’ major triad. For a larger major seven or major nine chord the root note is followed by the symbol M, Maj or and then the extension (number) of the chord (7, 9, 11 or 13) is added.
So, a ‘G major ninth chord symbol can be written as;
MINOR CHORD SYMBOLS
Three note minor chords (triads) use the root note followed by the symbol m, min or -.
For example, the symbol for a ‘G Minor’ chord can be one of the following: Gm, Gmin or G-
For a larger minor seventh or minor ninth chord symbol the number of the chord (7, 9, 11 or 13) is added.
So, a ‘G Minor Seventh’ chord symbol would be one of the following: Gm7, Gmin7 or G-7.
DOMINANT CHORD SYMBOLS
Dominant chord symbols use the root note followed by the number.The symbol for a ‘G Dominant Seventh’ chord is ‘G7’.
CHORD CONSTRUCTION SUMMARY
There are broadly three types of chord; MAJOR, MINOR and DOMINANT.
Most chord formulae within these chord types progress in third intervals (1:3:5:7 etc), or odd numbers, but they are adjusted slightly in order to create these chord types.
MAJOR chord formulae are based on 1 : 3 : 5. This is called a triad. When larger major chords are built, odd numbers up to the required chord size are used. So, for a major ninth chord odd numbers up to 9 are used (1:3:5:7:9).
MINOR chord formulae are based on 1 : b3 : 5. The flattened third note is the characteristic of a minor triad. When larger minor chords are built, odd numbers up to the required chord size are used. However, the seventh note must also be flattened. So, for a minor ninth chord odd numbers up to 9 are used and the seventh and third are flattened (1:b3:5:b7:9).
DOMINANT chord formulae are based on 1 : 3 : 5 : b7. The flattened seventh note is the characteristic of a dominant chord. When larger minor chords are built, odd numbers up to the required chord size are used. So, for a dominant ninth chord odd numbers up to 9 are used and the seventh note is flattened (1:3:5:b7:9).
All other chords broadly fit into one of these three categories.
Some chords may have more notes than it is possible to play at one time on the guitar. For example a ‘C13’ has seven notes (C:E:G:Bb:D:F:A) and the guitar usually only has six strings. Therefore it is necessary to prioritise some of the notes and to leave out others.
Depending on the context, the most important notes in this example are:
‘C’ – the root and the foundation of the chord.
‘E’ – the third indicates if the chord is major or minor.
‘Bb’ – the seventh determines if the chord is a major or dominant seventh.
‘A’ – the 13th is specified in the chord formula.
Some chords may seem difficult to work out.
For example, what are the notes in an Am7b5 (‘A’ minor seventh flattened fifth) chord?
1) Refer to the major scale of the root note:
A B C# D E F# G# A.
2) Extend the scale so it goes up two octaves.
A B C# D E F# G# A B C# D E F# G# A
3) Then number each note of the major scale.
4 ) Next, you need the chord formula for the type of chord you are building. This is a minor seventh (m7) with a flattened fifth (b5).
The formula for a minor seventh chord is: 1 : b3 : 5 : b7
Then you need to flatten the fifth note. This results in: 1 : b3 : b5 : b7
Finally, take these notes from the ‘A’ major scale.
1 = A
b3 = C
b5 = Eb
b7 = G
Make sure that you understand the difference between MAJOR SEVEN and DOMINANT SEVEN chords.
© Carlos Thrale 2014