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CHORDS

Intervals

To understand chords, we must first take a close look at intervals.

Interval
The space between two notes.

A chord has to have a minimum of 3 notes, called a chord triad. A chord triad consists of 2 intervals. The smallest interval in western music is the half-step. On a piano keyboard, this would be playing 2 notes without any other notes in between them. B - C, C - C#, E - F, Gb - G, are all examples of half-step intervals.

The next largest interval is the whole step. A whole step consists of 2 half steps. B - C#, C - D, E - F#, Gb - Ab are all examples of whole step intervals.

The next largest interval is the minor third. A minor third consists of 1 1/2 steps. The interval which is larger than the minor third is the major third, which consists of 2 whole steps (or 4 half steps).

The following chart shows the intervals starting from G.

Interval Name
G - Ab half-step
G - A whole-step
G - Bb minor third
G - B major third


* There are more intervals than the ones listed, but for purposes of learning chords, only the half-step, whole-step, minor third and major third intervals will be covered.

There are only 4 types of chord triads; major, minor, augmented and diminished. These chords are defined by their intervals.

The following is a chart of the various G chord triads, with the notes of the chord and interval names listed:

G Chord Notes of Chord Order of Intervals
G Major G B D Maj-3rd Min-3rd
G Minor G Bb D Min-3rd Maj-3rd
G Augmented G B D# Maj-3rd Maj-3rd
G Diminished G Bb Db Min-3rd Min-3rd

Knowing the intervals which make up chords, will allow a person to find chords without any additional aids.

Seventh Chords

If we extend the chord triad by giving it a fourth note, we get 7th chords. The following chart lists the most common 7th chords for G along with the appropriate intervals:

G 7th Chord Notes of Chord Order of Intervals
G Major 7 G B D F# Maj-3rd Min-3rd Maj-3rd
G Dominant 7 G B D F Maj-3rd Min-3rd Min-3rd
G Minor 7 G Bb D F Min-3rd Maj-3rd Min-3rd
G Half-Diminished 7 G Bb Db F Min-3rd Min- 3rd Maj-3rd
G Diminished 7 G Bb Db E Min-3rd Min-3rd Min-3rd

You may want to go further and chart out the intervals for 5, 6 and 7 note chords as well. I will not go any farther than charting 4 note chords.

Applying chords to music

To apply chords to music, first find out the key of the song. Then by harmonizing the corresponding scale, or simply using the number system, one can find all of the chords which work for a given key.

An example would be if a song is in the key of A major, it scale would be:

  • A B C# D E F# G#

Any chord which contains notes derived from this scale will work in this key. So, A major 9 (A C# E G# B) works since all it's notes are derived from the A major scale. Db major (Db F Ab) won't work within the key because this chord contains an F natural instead of an F sharp. But try it anyhow, it may work in the song even though it doesn't fit the key. Don't be afraid to place chords in a song which aren't derived from it's key(s). In other words, don't limit yourself to the key of a song/progression. Keys are to be thought of as guidelines.

Chord naming conventions

Let's use chords derived from the C major scale as examples:

C D E F G A B

Chords are derived from numbering the scale degrees of the corresponding root. (C=1, D=2, E=3, etc.). When the notes of the scale go into another octave, the numbers continue.

C  D  E  F  G  A  B  C  D  E   F   G   A
1  2  3  4  5  6  7  8  9  10  11  12  13

A chord triad will contain the 1, 3 and 5. A Seventh chord will be numbered, 1, 3, 5, 7. Here is list of the basic chord names and their corresponding numbers:

Number of notes Name
1 3 5 Triad
1 3 5 7 Seventh
1 3 5 7 9 Ninth
1 3 5 7 9 11 Eleventh
1 3 5 7 9 11 13 Thirteenth

Notice the pattern. The notes of all chords (except suspended chords, 6th chords and some altered chords) are derived from choosing a tonic, and building the rest of the notes from the corresponding scale by skipping every other note of the scale.

Naming Chord Triads

Earlier, I demonstrated how to find the name of chord triads using intervals. The chart below illustrates how a chord name can be found by examining the numbers of the major scale in which it is derived from.

C Chord Triad Notes of Chord Numbers of Chord
C Major C E G 1 3 5
C Minor C Eb G 1 b3 5
C Augmented C E G# 1 3 #5
C Diminished C Eb Gb 1 b3 b5


Suspended Chords
A chord which has its third either raised to the 4th or lowered to the 2nd scale degree.

C F G = C sus 4 (sus 4 chords are usually written without the "4", i.e., "C sus"

C D G = C sus 2

There has been some confusion about suspended chords. I once saw a chord labeled as a Minor sus 4. This is an erroneous name because by definition, a suspended chord has no third, but a minor chord has to have a flatted third. The intended chord was a Minor add 11 chord.

The following is a list of most, if not all, of the possible C chords and their corresponding names.

Notes of Chord Chord Name
C E G C Major
C Eb G C Minor
C E G# C Augmented
C Eb Gb C Diminished
C Eb Gb Bb C Half-diminished
C Eb Gb A C Diminished 7
C F G C Suspended 4
C D G C Suspended 2
C F G Bb C Suspended 7
C F G Bb D C Suspended 9
C F G Bb D F C Suspended 11
C F G Bb D F A C Suspended 13
C E G B C Major 7
C E G Bb C Dominant 7
C Eb G Bb C Minor 7
C E G A C Major 6
C Eb G A C Minor 6
C E G A D C 6/9
C Eb G A D C Min 6/9
C Eb G B C Minor/Major 7
C E G# B C Maj 7 Sharp 5
C E G# Bb C Dom 7 Sharp 5
C E Gb B C Maj 7 Flat 5
C E Gb Bb C Dom 7 Flat 5
C Eb G# Bb C Min 7 Sharp 5
C E G Bb D# C Dom 7 Sharp 9
C E G Bb Db C Dom 7 Flat 9
C E G B D C Maj 9
C E G Bb D C Dom 9
C Eb G Bb D C Minor 9
C Eb G B D C Min/Maj 9
C E G# B D C Maj 9 Sharp 5
C E G# Bb D C Dom 9 Sharp 5
C Eb G Bb Db C Min 7 Flat 9
C E Gb B D C Maj 9 Flat 5
C E Gb Bb D C Dom 9 Flat 5
C Eb Gb Bb D C Min 9 Flat 5
C E G B D# C Maj 7 Sharp 9
C E G B Db C Maj 7 Flat 9
C E G Bb Db C Dom 9 Flat 9
C E G# B D# C Maj 7 Sharp 5 Sharp 9
C E G# Bb D# C Dom 7 Sharp 5 Sharp 9
C E G# B Db C Maj 7 Sharp 5 Flat 9
C E G# Bb Db C Dom 7 Sharp 5 Flat 9
C E Gb B D# C Maj 7 Flat 5 Sharp 9
C E Gb Bb D# C Dom 7 Flat 5 Sharp 9
C Eb G B D F C Min/Maj 11
C Eb G Bb D F C Min 11
C Eb Gb Bb D F C Min 11 flat 5
C E G B D F C Maj 11
C E G# B D F C Maj 11 Sharp 5
C E G B D# F C Maj 11 Sharp 9
C E G# B D# F C Maj 11 Sharp 5 Sharp 9
C E Gb B D F C Maj 11 Flat 5
C E G B Db F C Maj 11 Flat 9
C E Gb B Db F C Maj 11 Flat 5 Flat 9
C E G Bb D F C Dom 11
C E G# Bb D F C Dom 11 Sharp 5
C E G Bb D# F C Dom 11 Sharp 9
C E G# Bb D# F C Dom 11 Sharp 5 Sharp 9
C E Gb Bb D F C Dom 11 Flat 5
C E G Bb Db F C Dom 11 Flat 9
C E Gb Bb Db F C Dom 11 Flat 5 Flat 9
C E G Bb D F A C Dom 13
C E G B D F A C Maj 13
C Eb Gb Bb D F A C Min 13 flat 5
C E G Bb Db F A C 13 Flat 9
C E G Bb D# F A C 13 Sharp 9
C E G Bb D# F A C 13 Sharp 9


* "Dom" is an abbreviation for Dominant. All 7th chord names without the "Dominant" or "Major" qualifier (C 7th) are implied to be Dominant seven chords. "Half-diminished" is also called "Minor 7 flat 5" and is listed twice. "Augmented" is an alternative name for any chord with a sharp 5. Ex; C Dom 7 Sharp 5 = C Augmented 7

The names of the chords are cumulative. In other words, if a chord is called a ninth, it must contain all of the triad numbers below nine. An eleventh chord must contain 1 3 5 7 9 11 in order to be called a true "eleventh" chord. If a chord does not hold to the pattern, say the alleged eleventh is missing the 9, containing 1 3 5 7 11, then it is said to be a "seven add eleven". For instance, C E G B F is a C major 7 add eleven, while C E G B D F is a legitimate C major eleven chord. Here are some more examples:

Notes of Chord Chord name
D F# A E D major add 9
Eb G Bb Db A C Eb Dom 7 add 11 add 13
G B D A C G major add 9 add 11

Inversions

The best way to define an inversion is to illustrate a few:

The C major triad has three inversions:

  • C E G - root inversion
  • E G C - 1st inversion
  • G C E - 2nd inversion

C Major 7 has four inversions

  • C E G B - root inversion
  • E G B C - 1st inversion
  • G B C E - 2nd inversion
  • B C E G - 3rd inversion

C G B E is not an inversion. All the notes of the chord must be present and no note can be skipped, only the sequence of the notes can be altered in a chord inversion.

Voicings

A chord voicing is different from a chord inversion in that a note can be skipped or repeated in a chord voicing. Again, the best way to teach about chord voicings is to illustrate them:

C G B E is a chord voicing of C major 7.

C B E G is a chord voicing of C major 7

G C E G is a chord voicing of C major 7.

C G C B E is a chord voicing of C major 7.

B G E C E is a chord voicing of C major 7.

As chords get bigger (elevenths and thirteenths), most musicians will tend to drop one note of the chord. Usually, (this is not a rule) the eleventh is the first note to go in a thirteenth chord, thus technically making the chord a 9 add 13 (assuming no other note is dropped).

One thing to keep in mind about voicings and inversions is that with bigger chords, voicings/inversions become increasingly important as to how the chord sounds. For instance, for the G major 7 chord, voiced G B D F#, this chord can sound "jazzy", while voiced B D F# G is too disonant because of the F# and G being placed right next to each other. The latter voicing is a rarely used one for this chord.

Alternate names for chords

In the notes above, I talked about some alternate names for chords (Half-diminished/Minor 7 b5 is one example). But some chords have alternate names which can be chosen based upon how the chord is being used within the context of the song/progression. Some examples are:

Notes of Chord Chord Name Chord Name
A C E G A minor 7 C major 6 (3rd inversion)
B D F A B half-diminished D minor 6 (3rd inversion)
G C D G suspended 4 C suspended 2 (1st inversion)

Augmented chords have 3 possible names, usually chosen based upon which inversion is being used:

Notes of Augmented Chord Chord Name
C E G# C Augmented
E G# C E Augmented
G# C E G# Augmented

So, which name should be used in which situations? Whichever is easiest. The way a chord is being used will help you in deciding upon its name. For instance, if the G sus 4/C sus 2 chord is used (the notes are G C D) before or after a G major chord, I'm more likely to call this a G sus 4 because I associate it with the preceding G chord. This is especially true if the bass note is a G since it is easier to think of such a chord as G sus4 rather than Csus2/G.