Chord Composition

A major triad is built of 2 intervals - a major third and a further minor third on top it.  Another way to look at this is a major third and a perfect fifth

A minor triad composed of a minor third and a further major third on the top.  In other words, a minor third and a perfect fifth

An augmented triad composed of a major third plus a major third, or in other words, a major third and an augmented fifth.

A diminished triad composed of a minor third and another minor third on top, or in other words a minor third and a diminished fifth.


C- Major chords are happy, simple, honest and bold composed of 1,3,5
Cm - Minor chords are sad and serious composed of 1,3b,5
Cmaj7 - Major seventh are pretty, delicate, sensitive and thoughtful composed of major+7
Cm7 - Minor seventh are pensive, moddy and introspective composed of minor+7b
C7 - Dominant 7 are sassy, outgoing and strong composed of major+7b
C6 - Major sixth are playful composed of major+6
Cm6 - Minor sixth are dark, sensuous, troubled composed of minor+6
Csus4 - Suspended 4 are regal and material composed of C without third (sus part)+4 (i.e. 1,4,5).  This chord creates a harmonic suspension and could be resolved by returning to the original triad
C9 - Ninth are energetic and lively composed of major+9 (or 2 raised to an octave)
Cm9 - Minor ninth are sad, tender and complex composed of minor+9
Cdim - Diminished are dark, strained and complex composed on a Minor with its fifth flatted (i.e. 1,3b,5b)
C+ - Augmented are anticipatory and full of movement composed on Major with its fifth sharped
Cm7/b5 - Minor 7, flat 5 or half diminished are disparaging, sorrowful, difficult and deep composed of Cm7 with 5b

In summary,
Cmaj7 = C + 7
C7 = C + 7b
C6 = C + 6
C9 = C + 9 = C + 2
C+ = C with 5#

Cm = C with 3b
Cm7 = Cm + 7b
Cm6 = Cm + 6
Cm9 = Cm + 9
Cdim = Cm with 5b

Csus4 = C - 3 + 4