How do we construct a chord? What does the notation mean? Here are all the tools you need to create chords from scratch and understand the meaning of the chord notation.
The major scale
In order to start constructing chords, we need to find the degrees of the major scale over 2 octaves. To obtain the notes of the major scale, start from the root and apply the formula of intervals W-W-s-W-W-W-s (W = whole tone, s = semitone). We get this table with the degrees from 1 to 14, I chose A Major because not everything is in C.
| A | * | B | * | C# | D | * | E | * | F# | * | G# |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | |||||
| A | * | B | * | C# | D | * | E | * | F# | * | G# |
| 8 | 9 | 10 | 11 | 12 | 13 | 14 |
We can split the degrees in 3 sections that will help us build a chord.
- Degrees 1 to 5; Triad section
- Degrees 6 and 7; Lower extensions section
- Degrees 8 and over; Upper extensions section
Triad
The basic chord consists of 3 different notes chosen in the triad section, the formula is to stack the degrees upwards while always skipping one, so we get 1 – 3 – 5 as the base for our triad (commonly referred as stacked thirds). The only exception to this formula is when we ‘suspend‘ the 3rd degree to an adjacent degree.
The following table shows the degrees from 1 to 5, we extend the notes from the major scale to get different combinations of triads. To do this we change the quality of the interval from the degree to the root, M = major interval, m = minor interval, P = perfect interval, d = diminished interval, and a = augmented interval.
| A | Bb | B | C | C# | D | Eb | E | E# |
| 1 | m2 | M2 | m3 | M3 | P4 | d5 | P5 | a5 |
Here are all the triads that we can use, 4 using the third and 2 suspended.
| 1-M3-P5 | Major | A-C#-E | A | |
| 1-m3-P5 | Minor | m | A-C-E | Am |
| 1-m3-d5 | Diminished | ° | A-C-Eb | A° |
| 1-M3-a5 | Augmented | + | A-C#-E# | A+ |
| 1-M2-P5 | Suspended 2nd | sus2 | A-B-E | Asus2 |
| 1-P4-P5 | Suspended 4th | sus4 | A-D-E | Asus4 |
Lower extensions
Now that we have our triad, we have the possibility to add extensions, they are optional but they add color to a chord. There are two options with the lower extensions. You can keep using the formula from the triads and extend by skipping a degree to get to 7th (1-3-5-7), this will open a lot of new possibilities. Or instead, you can break the formula and use the 6th, but this time you get only a few options.
| F# / Gb | G | G# |
| M6 / d7 | m7 | M7 |
Sixth chords
The sixth chords, because they break the formula, are not widely used, but they exist. There are three variations that you can use.
| 1-M3-P5-M6 | Sixth | 6 | A-C#-E-F# | A6 |
| 1-M3-P5-M6-9 | Six-nine | 6/9 | A-C#-E-F#-B | A6/9 |
| 1-m3-P5-M6 | Minor Sixth | m6 | A-C-E-F# | Am6 |
Seventh chords
There are many combinations possible of adding a 7th to a triad, the formula is simple but it has a big exception. When we add a M7 to the triad, we must specify maj7, while we only add 7 when we use the m7. Also when we add a 7th to a diminished triad, the formula is slightly changed.
| Major-M7 | Major seventh | maj7 | A-C#-E-G# | Amaj7 |
| Major-m7 | Dominant seventh | 7 | A-C#-E-G | A7 |
| Minor-m7 | Minor seventh | 7 | A-C-E-G | Am7 |
| Minor-M7 | Minor major seventh | maj7 | A-C-E-G# | Am/maj7 |
| Augmented-m7 | Augmented seventh | 7 | A-C#-E#-G | A+7 |
| Diminished-m7 | Half-diminished seventh | 7 | A-C-Eb-G | Aø7 |
| Diminished-d7 | Diminished seventh | 7 | A-C-Eb-Gb | A°7 |
Note: You can also use the suspended triads to create 7th chords, for example, A-D-E-G would be A7sus4.
Note: Another way to notate a half-diminished chord is by using this notation: Am7b5.
Upper extensions
You can go beyond the 7th by using upper extensions. But this time the formula of stacked thirds must be respected. So in order to use the 9th, you need the 7th, to use the 11th you need the 9th, and to use the 13th you need the 11th.
Here are the upper extensions that are available. Notice that the degrees 8-10-12-14 are not there, they are the equivalent to degrees 1-3-5-7 and cannot be repeated (also b11 = M3 and #13 = m7). Another important thing, for these extensions the chord notation uses the flat (b) and sharp (#) symbols instead of the interval quality used earlier.
| * | Bb | B | B# | * | D | D# | * | F | F# | * | * |
| b9 | 9 | #9 | 11 | #11 | b13 | 13 |
Note: The #9 extension can only be used if a M3 exists in the chord, else it becomes a m3.
The notation of the extensions depends on two things. First, the highest unaltered extension is the number to be used. Then if the M7 is used, the maj will precede the number, if it’s the m7 then nothing else is added. All altered extension are added after that, they can be separated by a ‘/’ for readability, but it’s optional. For example, the chord built with 1-M3-P5-M7-9-#11 would be noted Amaj9#11, the chord built with 1-M3-P5-m7-b9 would be noted A7b9.
Additions / Subtractions
Sometimes we want extensions that don’t follow the strict rules of the stacked thirds. In these cases, we can use the addition or subtraction notation to qualify the chord. The addition, notated add, is how we add an extension without the need to include all the stacked thirds below, while the subtraction, notated no, is how we omit an extension from all the stacked thirds of a chord.
To demonstrate both cases, let’s use this chord: A – C# – E – B. The analysis of the notes gives us these intervals, 1 – M3 – P5 – 9. The first conclusion is to see the chord as a Major triad plus an added 9th, in this case, it would be noted like this: Aadd9. But it could also be a 9th chord without the 7th, this would be noted as A9no7th. But when there is more than one option like this, we always choose the more simple, less ambiguous one, in this case, it’s definitely Aadd9.
Inversions / Slash chords
Generally, the root of the chord is also the lowest note by pitch, but if the voicing used to play the chord has another note as the lowest, it needs to be noted. Inversions are when another note from the chord is used as the lowest note, for example on a simple triad, if the 3rd is the lowest note, it’s called 1st inversion, if the 5th is the lowest note, it’s the 2nd inversion. These terms come from a more classical background, there is a way to notate these inversions but I won’t get into that in this article.
In popular music, we simply notate the non-root lowest note by adding it at the end of the notation, preceded by a ‘/’ sign. So an A major chord with the 3rd as the lowest note (C# – E – A) would be noted A/C#.
Slash chords are a similar concept with similar notation, but they are a bit different in context. Let’s say we have a chord with this voicing: B – A – C# – E. The lowest note is B, if we assume it’s also the root of the chord, we get a B9sus4, but without the B this is a simple A major chord. In this case, we need context, does the melody over the chord outlines a B chord or an A chord? In the chord progression, does the chord before naturally leads to a B or an A? Is the lowest note far in pitch from the rest of the chord? All these questions can help name the chord correctly. If we feel confident that the context calls for an A major chord with a B note on the bass to add some tension, then we can notate this chord like this: A/B.
Chord notation
Now that we know a little more about how to construct chords, how do we notate them? Here is the template to use:
[root][triad][extensions][suspension][additions][substractions][inversion]
- Root; the base note of the chord, required
- Triad; the base triad of the chord, required unless suspended
- Extensions; the extension degree number plus all altered extensions, optional
- Suspension; if the triad is suspended, this will replace the triad, optional
- Additions; added extension, degree number with the flat or sharp symbol if necessary, optional
- Subtractions; removed extension, degree number with ordinal suffix, optional
- Inversion; lowest note different from the root, preceded with a slash ‘/’, optional
Voicings
There are two types of voicings for chords, close and open positions. The close position is the perfect stacked thirds voicing, it’s great in theory but it’s really rare in practice, especially for guitars. The open position is more common, but it leads to many variations of voicings, the more you add notes to the chord, the more you have different voicings.
The rule for open position voicings is simple, you can put all notes of the chord in any order and as many times as you want, as long as the lowest note is correctly noted (root or inversion). The degrees that make a chord are useful to qualify them, but they don’t represent a required pitch order. It means that you can have a 3rd with a pitch higher than a 7th, you can have two 5ths at different octaves and only a single root. In fact, only the close position would put the pitches accurately.
Accepted omissions
On all instruments where you can play chords, you have limitations, especially guitar players. A full 13th chord has 7 notes while the guitar only has 6 strings, so there is obviously a problem. So there are cases where it’s ok to omit some notes of the chord, without the need to specify on the notation. In most cases, the perfect 5th is the first note to go, because it doesn’t have a great influence on the color of the chord. Another common omission is the 11th on a 13th chord because it clashes with the M3.
In jazz, it’s common for musicians to play only the extensions while other musicians play the main triad of the chord. So the chord on the instrument may not look like the chord of the overall harmony.
Examples
| A-C#-E-G# | 1-M3-P5-M7 | Amaj7 |
| A-C#-E-F# | 1-M3-P5-M6 | A6 |
| A-C-E-G-B-D | 1-m3-P5-m7-9-11 | Am11 |
| A-D-E-G-Bb | 1-P4-P5-m7-b9 | A7b9sus4 |
| A-C#-E-G#-B-D# | 1-M3-P5-M7-9-#11 | Amaj9#11 |
| E-A-C-G | P5-1-m3-m7 | Am7/E |
