Chord Construction
Chords are combinations of three or more musicial pitches. They are constructed based on the notes in the major scale. The simplest chord is a major chord. For the moment, it's simplest to stick with the key of C because it has no sharps or flats. Chords follow up the scale, skipping in steps of two. I.e., this is the C-Major scale:
| I
| II
| III
| IV
| V
| VI
| VII
| VIII
|
| C
| D
| E
| F
| G
| A
| B
| C
|
So to make a major chord, start with the I, and skipping up by twos, add the III and V notes:
| I
| II
| III
| IV
| V
| VI
| VII
| VIII
|
| C
| D
| E
| F
| G
| A
| B
| C
|
This selects your major chord, C-major: C,E,G
All other chords are derived from the major chord. A minor chord, for example, is a major chord, with a flat third. I.e., instead of C,E,G it would be C,Eb,G. A diminished chord is done by adding a flat to the third and fifth notes. i.e., C, Eb, Gb. An augmented chord is done by adding a sharp to the fifth. I.e., instead of C,E,G it would be C,E,G#.
There are only two other traditional three-note chords which you'll find-- they're both forms of the suspended chord. They replace the third with either a second or a fourth. I.e., Csus2 would be C,D,G. Csus4 would be C,F,G.
To summarize, here are all the examples of three-note chords using C as the root:
| Cmaj (C-major)
| C,E,G
|
| Cmin (C-minor)
| C,Eb,G
|
| Co (C-diminished)
| C,Eb,Gb
|
| C+ (C-augmented)
| C,E,G#
|
| Csus2 (C, with a suspended 2)
| C,D,G
|
| Csus4 (C, with a suspended 4)
| C,F,G
|
Moving onto 4-note chords becomes slightly more complicated. The 4-note chords usually involve the seventh note, as follows:
| I
| II
| III
| IV
| V
| VI
| VII
| VIII
|
| C
| D
| E
| F
| G
| A
| B
| C
|
Thus, your major seventh chord is C,E,G,B. For whatever reason, musical convention distinguishes between the major seventh chord and the basic seventh chord. If you see Cmaj7, expect to play the C,E,G,B combination. But if you see C7, that actually means you should flat the seventh note. I.e., C,E,G,Bb. Otherwise, it's just a matter of combining the three-note combinations with whatever you've added. I.e., Cmin, maj7 would mean a minor chord with a major seventh. I.e., C,Eb,G,B. But Cmin7 would be C,Eb,G,Bb. Common four-note chord combinations are:
| Cmaj7 (C-major7)
| C,E,G,B
|
| C6 (C-major with an added 6)
| C,E,G,A
|
| C7 (C-7)
| C,E,G,Bb
|
| Cmin7 (C-minor7)
| C,Eb,G,Bb
|
| Co,b7 (C-diminished with a flat 7)
| C,Eb,Gb, Bb
|
| Co7 (C-diminished with a double-flat 7)
| C,Eb,Gb, Bbb
|
| C+,maj7 (C-augmented w/major seventh)
| C,E,G#,B
|
| C+7 (C-augmented w/7)
| C,E,G#,Bb
|
The notation for further chord extensions can be confusing at first, because instead of stopping at the octave point, the notes keep going on beyond it, as follows:
| I
| II
| III
| IV
| V
| VI
| VII
| VIII
| IX
| X
| XI
| XII
| XIII
|
| C
| D
| E
| F
| G
| A
| B
| C
| D
| E
| F
| G
| A
|
Furtheremore, there are some simplifications which are not always clear when first exploring extended chords. A C9 chord, for example, is merely a C7 chord with an added 9. I.e., C,E,G,Bb,D. A C13 is a C7 chord with an added 9 and 13 (but not an added 11). Thus, C,E,G,Bb,D,A. Extended chords can also have annotations to the individual notes added, such as a C7b13, which would be C,E,G,Bb,Ab.
A Cmaj9, on the other hand, is a Cmaj7 chord, with an added 9. I.e., C,E,G,B,D. And, for some reason, a C6/9 chord is identical to a C13 chord, minus the 7. I.e., instead of C,E,G,Bb,D,A it's C,E,G,D,A
Common extended chords are:
| Cmaj9 (C-major9)
| C,E,G,B,D
|
| C9 (C-9)
| C,E,G,Bb,D
|
| C13 (C-13)
| C,E,G,Bb,D,A
|
| C7b13 (C-7 with a flat-13)
| C,E,G,Bb,D,Ab
|
| Cmin9 (C-minor9)
| C,Eb,G,Bb,D
|
| Cmin11 (C-minor11)
| C,Eb,G,Bb,F
|
| Cmin,b13 (C-minor with a flat-13)
| C,Eb,G,Bb,D,Ab
|