The term chord spelling means naming the individual notes of chords, i.e. the chord tones.
The major scale of the chord root is the reference scale for all chord-spelling formulae. It is therefore important to know the major scale in all keys.
There are forty chord types explained in this segment. Understanding the spelling of these chords will enable you to spell any chord in any key, provided you know the major scale in any key.Triads
A triad is a three-note chord whose notes can be placed in consecutive major or minor thirds.
There are four triad types:
Major triad. The formula is notes 1 3 5 (from the major
scale of the chord root). E.g. the chord symbol C means a C major
triad containing the notes C E G.
Minor triad. The formula is notes 1 b3 5 (from the major scale of the chord root). E.g. the chord symbols Cm, Cmin or C- mean a C minor triad containing the notes C Eb G.
Diminished triad. The formula is notes 1 b3 b5 (from the major scale of the chord root). E.g. the chord symbols Cdim or C° mean a C diminished triad containing the notes C Eb Gb.
Augmented triad. The formula is notes 1 3 #5 (from the major scale of the chord root). E.g. the chord symbols Caug, C+ or C(#5) mean an augmented triad containing the notes C E G#.
Four-note chords have scale tones 1 3 5 7, i.e. consecutive thirds below the octave. The thirds, fifths and sevenths can be lowered by a semitone. The fifths can also be raised by a semitone.
Chords with upper extensions
In chord spelling, the term "upper extensions" applies to notes above the octave, i.e. compound intervals. The sequence of consecutive thirds is 1 3 5 7 9 11 13 which contains all notes of the 7-note reference (major) scale (E.g. C E G B D F A). Therefore, the upper extensions are notes 9 11 13 which equate to scale tones 2 4 6.
Here are some guidelines and rules:
It is understood that the chord spelling contains all consecutive thirds below the number immediately following the chord root. E.g. C9 contains five notes, which are C E G Bb D.
The chord quality is always major unless indicated by a minor or diminished abbreviation or symbol after the chord root letter. Therefore, e.g., a Cm9 chord symbol means it is a minor chord type with a minor third (b3) and not a minor 9th (b9) and the 9th is major as no alteration (b9 or #9) is indicated. If the chord symbol does not indicate "maj7" the 7th will always be, with one exception, a flat seventh (b7). The exception is in the diminished seventh chord, where the seventh is diminished, i.e. double flat seventh (bb7).
The indication "maj" always denotes the 7th only. E.g. Cmaj9 has the notes C E G B D. The 9th (D) is already major as no alteration (b9 or #9) is indicated.
Upper extensions are understood to be extracted from the major scale of the chord root, unless indicated otherwise. E.g. Cmaj13(#11) has the notes C E G B D F# (the #11) A.
Chords with suspension (sus chords)
The suspension, usually noted as "sus" always denotes the 4th.
Chords with omissions
Chords with single-note additions