Diatonic chords are a series of chords built from the major scale (or natural minor scale). These diatonic chords and the chord progressions made from them make up most songs in Western music. Even songs that change keys use the logic of diatonic chords in their chord progressions.
In this article, we’ll unravel the logic behind diatonic chords and help you understand how musicians construct and use them. We’ll cover—
- What diatonic chords are
- Major diatonic chords
- Minor diatonic chords
- Diminished chords
- Diatonic triads
- Diatonic seventh chords
- Diatonic chord progressions
If you want to master music theory concepts like diatonic chords but don’t know where to start, check out the Learn Jazz Standards Inner Circle. The Inner Circle is designed to help players like you take your music theory and jazz chops to the next level.
Want to improve in 30 days or less? Check out the Inner Circle.
Table of Contents
What Are Diatonic Chords?
Diatonic chords are built from the notes of a major scale or a natural minor scale. The intervallic relationships between the notes in the major or natural minor scale create a series of chords with different qualities.
These chords are diatonic chords, and they are unified by their relationship to the major scale from which they were built.
If you are building diatonic triads from the major scale or minor scale, you’ll find three different chord qualities:
- major triads
- minor triads
- diminished triads
If you are building diatonic seventh chords from the major scale or natural minor scale, you’ll find four different chord qualities:
- Major seventh chords
- Dominant chords
- Minor seventh chords
- Half-diminished chords
As you’ll see below, these diatonic chord qualities are derived from the scale degrees in either the major or natural minor scale. These two scales are actually the same scale in terms of their note sequences, which are identical. This is the idea behind the concept of modes.
For more on modes of the major scale, check out our guide to musical modes.
The combination of whole and half steps found in the major scale or minor scale formula gives rise to seven diatonic chords.
It’s important to note that the relationships between diatonic chords don’t change, even when you change keys. Diatonic chords represent the harmonic structure found within the major scale (or minor scale).
For example, the I chord in major keys is always a major chord, whether using the C major scale, the G major scale, or any other major scale to construct your diatonic chords. The ii chord is always minor, etc.
We explore the equivalence between major keys and minor keys in our article on relative and parallel minor keys.
Understanding Roman Numerals
To understand diatonic chords and diatonic chord progressions, you’ll first need to know how Roman numerals work in music theory.
Musicians use Roman numerals to help them with harmonic analysis. Each scale degree of the major scale or minor scale is assigned a Roman numeral based on its relationship to the tonic chord (or root note).
- Upper-case numerals represent major chords
- Lower-case numerals represent minor chords
- Diminished chords are lower-case with a diminished symbol, or “°.”
Since the major scale has seven notes, we can construct seven diatonic chords from each scale degree. This helps musicians quickly analyze the harmonic structure of songs and easily transpose chord relationships from a particular key to other keys.
Let’s look at how Roman numerals work for major and minor keys. We’ll use the relative keys of C major and A minor.
Major Key Roman Numerals
- C – I
- D – ii
- E – iii
- F – IV
- G – V
- A – vi
- B – vii°
Minor Key Roman Numerals
- A – i
- B – ii°
- C – III
- D – iv
- E – v
- F – VI
- G – VII
Building Diatonic Chords From the Major Scale
Let’s discuss how to build triads. Western music primarily uses tertiary harmony, which is harmony based on thirds. Triads are three-note chords consisting of a root note, a third, and a fifth (an additional third above the third!).
When building diatonic triads, we use the scale degrees of the major scale to determine what kind of third or what type of fifth we use.
Using our knowledge of musical intervals, we know that a third can be major (four half steps) or minor (three half steps). A fifth can be perfect, diminished, or augmented. In the diatonic chord series, we’ll never encounter an augmented fifth. However, we will find perfect and diminished fifths.
For more on musical intervals like minor thirds and major thirds, check out our crash course on music intervals.
A C major triad consists of a major third between C and E and a perfect fifth between C and G.
Let’s build all the diatonic triads from each note of the C major scale to find all of our major scale diatonic chords. You can also do this for the minor scale, but we’ll stick to the major scale for our example.
C Major Chord (or I Chord)
- C-D-E-F-G-A-B-C-D-E-F-G-A-B-C
The tonic chord (I chord) is a C major chord (C, E, G):
- 5th: G
- 3rd: E
- Rt: C
D Minor Chord (or ii Chord)
- C-D-E-F-G-A-B-C-D-E-F-G-A-B-C
The ii chord is a D minor chord (D, F, A):
- 5th: A
- 3rd: F
- Rt: D
E Minor Chord (or iii Chord)
- C-D-E-F-G-A-B-C-D-E-F-G-A-B-C
The iii chord is an E minor chord (E, G, B):
- 5th: B
- 3rd: G
- Rt: E
F Major Chord (or IV Chord)
- C-D-E-F-G-A-B-C-D-E-F-G-A-B-C
The IV chord is an F major chord (F, A, C):
- 5th: C
- 3rd: A
- Rt: F
G Major Chord (or V Chord)
- C-D-E-F-G-A-B-C-D-E-G-F-G-A-B-C
The V chord is a G major chord (G, B, D):
- 5th: D
- 3rd: B
- Rt: G
A Minor Chord (or vi Chord)
- C-D-E-F-G-A-B-C-D-E-G-F-G-A-B-C
The vi chord is an A minor chord (A, C, E):
- 5th: E
- 3rd: C
- Rt: A
B Diminished Chord (or vii° Chord)
- C-D-E-F-G-A-B-C-D-E-F-G-A-B-C
The vii° chord is a B diminished chord (B, D, F):
- 5th: F
- 3rd: D
- Rt: B
Classifying Diatonic Triads
Here are all the major scale diatonic chords (triads) you can build from the C major scale in order:
It helps to quickly know the chord quality of each of the seven diatonic chords when thinking about diatonic chord progressions. That’s why classifying diatonic chords by their chord quality is important. Let’s classify the seven diatonic triads by chord quality.
Major Diatonic Chords
In major keys, there are three major chords: the I chord, the IV chord, and the V chord.
Major Diatonic Chords:
- I chord (tonic chord): C Major
- IV chord (sub-dominant chord): F Major
- V chord (dominant chord): G Major
In minor keys, the major chords are the III chord, the VI chord, and the VII chord. In A minor, they’d be:
- III chord: C Major
- VI Chord: F Major
- VII Chord: G Major
Notice how the chords are the same in relative major and minor keys. It’s the number that changes.
Minor Diatonic Chords
In major keys, there are three minor chords: the ii chord, the iii chord, and the vi chord.
Minor diatonic chords:
- ii chord (supertonic chord): D minor
- iii chord (mediant chord): E minor
- vi chord (submediant chord): A minor
In minor keys, the minor chords are the i chord, iv chord, and v chord. In A minor, they’d be:
- i chord: A minor
- iv chord: D minor
- v chord: E minor
The Diminished Chord
The diatonic chord built from the seventh scale degree is unique. It is a diminished triad. Diminished triads have a minor third and diminished fifth interval. In the diatonic series, this only happens on the seventh scale degree.
Diminished diatonic chords:
- vii° chord (leading tone chord): B diminished
For more on major triads, check out this article on major triads on guitar! Though the article focuses on how to play major triads on the guitar, the music theory is universal. Also, be sure to check out these other articles on minor triads and diminished triads.
BEFORE YOU CONTINUE...
If music theory has always seemed confusing to you and you wish someone would make it feel simple, our free guide will help you unlock jazz theory secrets.
Diatonic Seventh Chords
Knowing diatonic triads is important, but we must also explore diatonic seventh chords because jazz music predominantly uses seventh chords.
Building Diatonic Seventh Chords
Diatonic seventh chords are four-note chords that add one additional piece of harmonic information to the seven diatonic triads. Whereas triads are a root note, a third, and a fifth, seventh chords consist of a root note, a third, a fifth, and seventh scale degrees.
Let’s build one of the seven diatonic chords to demonstrate:
- C-D-E-F-G-A-B-C-D-E-F-G-A-B-C
Cmaj7 chord (C, E, G, B):
- 7th: B
- 5th: G
- 3rd: E
- Rt: C
For more on seventh chords, check out our guide to seventh chords on piano and guitar.
Two Types of Diatonic Major Chords Found in the Major Scale
When constructing triads, there was only one type of major diatonic chord—the major triad. However, when we add a seventh note into the mix, we end up with two types of major chords:
- Major 7th Chords
- Dominant 7th Chords
Major Seventh Diatonic Chords
The I chord and the IV chord are both maj7 chords. This means the musical interval between the root and the seventh scale degree is a major seventh interval.
Dominant Seventh Diatonic Chords
The V Chord is a dominant seventh chord. This means the musical interval between the root note and the seventh scale degree is a minor seventh interval.
Minor 7th Diatonic Chords
There are three minor seventh chords
Minor 7th Diatonic Chords:
- ii chord (supertonic chord): Dmin7
- iii chord (mediant chord): Emin7
- vi chord (submediant chord): Amin7
The minor key versions of these diatonic chords are :
- i chord: Amin7
- iv chord: Dmin7
- v chord: Emin7
Half-diminished Chord (or -7b5 chord)
Like diatonic triads, the diatonic chord built from the leading tone stands apart from the other diatonic chords in the series. It is a diminished triad with a minor seventh interval. These diatonic chords are called half-diminished chords or min7(b5) chords.
Here are all the diatonic seventh chords in the major key of C:
Diatonic Chord Progressions
Many songs are constructed entirely from basic diatonic chords that never change keys! These chord progressions move in predictable ways and only use chords from their diatonic series (or tonality/key).
Let’s look at two common diatonic chord progressions used in jazz music.
ii-V-I
The ii-V-I progression is omnipresent in jazz music—you can find it everywhere. Barring any alterations on the dominant chord, the common chord progression is completely diatonic.
I-vi-ii-V
Another common jazz turnaround, the I-vi-ii-V, and related iii-vi-ii-V chord progressions, are also completely diatonic.
However, many jazz chord progressions are non-diatonic, which means they use chord tones, extensions, and alterations not found within a major or minor key.
To learn more jazz chord progressions, check out this article on nine jazz chord progressions you need to know. And, for more on how to use borrowed harmony from outside the key (non-diatonic chords), check out this article on modal interchange!
Take Your Chord Knowledge To The Next Level. Join The Learn Jazz Standards Inner Circle!
If you want to take your chord knowledge to the next level, then you should check out the Learn Jazz Standards Inner Circle. We’ve got a great community and all the resources you need to help you take your jazz playing, musicianship skills, and music theory knowledge to the next level!
Improve in 30 days or less. Join the Inner Circle.
