Chord Structure

Chords - Symbols - Formulas

Chord structure consists of notes and intervals which can vary from 2-note chords and their respective intervals right up to 6-note chords and everything in between.

We will concentrate on the structure of 3-note chords for the start of this session, followed by a comprehensive chart detailing a variety of popular chords by name, type, symbol and formula.

Triads: 3-note chords

A triad is a 3-note chord stacked vertically in thirds. From lowest to highest pitch the chord consists of:

root - chord foundation
third - minor third (3 semi-tones) or major third (4 semitones)
fifth - minor or major third above the third interval. The interval above the root can be a diminished fifth (6 semitones), a perfect fifth (7 semitones), or an augmented fifth (8 semitones) - with the perfect fifth most commonly used in popular western music.
Please note that in triads, the root note doesn't have to be the lowest note in the chord due to the principle of inversion, but it will always remain the root note.

While the root note determines the chord's function and the interval from one note to the next is a third, the quality of the third is determined by the quality of the triad:

major triad infers the 3rd and 5th are untouched
minor triad infers the 3rd is flattened
diminished triad infers the 3rd and 5th are flattened
augmented triad infers the 5th is sharpened

Triad	Intervals	Formula	Semitones
Major	Major 3rd, Perfect 5th	1 - 3 - 5	0 - 4 - 7
Minor	Minor 3rd, Perfect 5th	1 - b3 - 5	0 - 3 - 7
Diminished	Minor 3rd, Dim 5th	1 - b3- b5	0 - 3 - 6
Augmented	Major 3rd, Aug 5th	1 - 3 - #5	0 - 4 - 8

If we were stacking thirds:

Triad	Thirds	Example	Semitones
Major	Major 3rd + Minor 3rd	C	C - E - G
Minor	Minor 3rd + Major 3rd	Cm	C - Eb - G
Diminished	Minor 3rd + Minor 3rd	Cdim	C - Eb - Gb
Augmented	Major 3rd + Major 3rd	Caug	C - E - G#

You will find a more detailed explanation about these intervals and stacking thirds including 4, 5 and 6-note chords along with relevant charts on the music chords page.

Chord Formula Chart

There are many symbols associated with chord types, and each one describes the type of chord and what notes will be played in the chord.

The following chart shows you the chords, symbols and formulas for almost every chord you will ever play. If you know your scales and chord formulas you will be able to calculate the notes of any chord for any instrument that utilizes chords.

? indicates the chord in question, therefore a C major chord can quite simply be written as C. Any chord written without other references or symbols is always a major chord.
() in the 'Formula' column indicates an optional note

Chords	Chord Type	Chord Symbols	Formula (notes)
Dyads:	Power, Double Stop, no3	5	1 - 5
2-note chords

Triads:	Major	?, M, Δ, ma, maj	1 - 3 - 5
3 note chords	Minor	m, - , mi, min	1 - ♭3 - 5
	Diminished	dim, º , m(♭5)	1 - ♭3 - ♭5
	Diminished 5th	-5	1 - 3 - ♭5
	Augmented	aug, +	1 - 3 - #5
	Suspended 4th	sus, sus4	1 - 4 - 5
	Suspended 2nd	sus2	1 - 2 - 5

7th Chords:	Dominant 7th	7, dom7	1 - 3 - 5 - ♭7
4 note chords	Minor 7th	m7, min7, -7	1 - ♭3 - 5 - ♭7
	Major 7th	maj7, M7, ∆7	1 - 3 - 5 - 7
	Minor Major 7th	mM7, minMaj7	1 - ♭3 - 5 - 7
	Suspended 7th	7sus4	1 - 4 - 5 - ♭7
	Augmented 7th	+7, aug7, 7+5, 7#5	1 - 3 - #5 - ♭7
	Augmented Major 7th	+M7, M7+5, M7#5	1 - 3 - #5 - 7
	7th Augmented Ninth	7+9	1 - 3 - 5 - ♭7 - # 9
	Half Diminished 7th	ø7, m7b5, m7-5, -7(b5)	1 - ♭3 - ♭5 - ♭7
	Diminished 7th	о7, dim 7	1 - ♭3 - ♭5 - ♭♭7
	7th Diminished Fifth	7 -5	1 - 3 - ♭5 - ♭7
	7th Flat Nine	7 -9	1 - 3 - 5 - ♭7 - ♭9

6th Chords:	Sixth	6	1 - 3 - 5 - 6
4 note chords	Minor 6	m6	1 - ♭3 - 5 - 6
5 note chords	Major 6th with added 9th	6/9	1 - 3 - 5 - 6 - 9

9th Chords	Ninth	9	1 - 3 - 5 - ♭7 - 9
5 note chords	Minor Ninth	m9	1 - ♭3 - 5 - ♭7 - 9
	Major Ninth	maj9, M9, ∆9	1 - 3 - 5 - 7 - 9
	Ninth Diminished Fifth	9 -5	1 - 3 - ♭5 - ♭7 - 9

11th Chords: 6 note	Eleventh	11	1 - 3 - 5 - ♭7 - (9) - 11

13th Chords: 7 note	Thirteenth	13	1 - 3 - 5 - ♭7 - (9) - (11) - 13

↓ Chord Structure

I hope you have enjoyed this session on Chord Structure. Next time you are playing and are unsure of how to play certain chords, knowing the formulas can be a great asset. You might be thinking, how can I remember all these formulas? The more you play and take note of chord formulas, the more you will remember them. This is especially useful when playing guitar and you need that chord high up the neck towards the guitar body. As long as you know your scales, formulas, and guitar notes, you can make up any chord - anywhere... very handy.