What are Diatonic Chords? How to Make a Chord Progression

What are diatonic chords?

Do we need to learn diatonic chords?

This article introduces “What are diatonic chords?” and “How to make chord progressions using diatonic chords.”

Diatonic chords are the underlying theory for creating chord progressions.

Learning diatonic chords makes it easier to compose and copy by ear!

In particular, copying by ear is a task that anyone who does music does.

By learning diatonic chords, you can finish copying by ear in a short time and save your precious time.

Let’s get started!

This article assumes that you understand:

・Understanding the Differences between Pitch, Interval, and Degree

・What are Scales and Keys?

What is Diatonic Chord

A diatonic chord is a chord that can be used with a certain key.

Therefore, if you know the key of the song, you can roughly understand the chords used, which is useful when copying by ear.

See below for keys.

What are Scales and Keys?

How to Make Diatonic Chords

The diatonic chords available in a key are made by layering every other note in that key’s scale within an octave.

• When 3 notes are superimposed: It is called a triad.
• When 4 notes are superimposed: It is called a 4-note chord (7th chord).

For example, to create a diatonic chord that can be used in the key of C major, layer 3 or 4 notes of the C major scale every other note within an octave.

The C major scale has 7 notes (C, D, E, F, G, A, B), and each note can be layered to create 7 diatonic chords.

( ) indicates the code in degree name.

The degree name is the chord expressed in Roman numerals based on the degree of the major scale.

By using the degree name, you can grasp the structure of the chord progression regardless of the key.

For example, the following chord progression structures are both “Ⅰ → Ⅳ → Ⅴ”.

• “C→F→G” in the key of C major
• “G→C→D” in the G major key

Below are the notes that make up the major key diatonic chords.

*If you do not understand the meaning of P1, M3, and P5, please see below.

Understanding the Differences between Pitch, Interval, and Degree

Like this, you can make diatonic chords with other keys as well.

Functions of Diatonic Chords

The code has three functions:

• Tonic (T): Stable sound
• Subdominant (SD): Slightly unstable sound
• Dominant (D): Unstable sound

The basic code for each function is called the three code.

In particular, tonic three chords are called tonic chords, subdominant three chords are called subdominant chords, and dominant three chords are called dominant chords.

A code that replaces the three code is called a substitute chord.

By the way, the last chord of a song is almost always a stable tonic chord (IM7).

Therefore, if you know the last chord of a song, there is a high possibility that you can also know the key of the song.

For example, if the last chord of a song is CM7, the key of that song is likely to be C major.

Chord Progression Using Diatonic Chords

How to Make a Chord Progression

Chord progressions can be created simply by connecting diatonic chords in a certain key as you like.

However, in the beginning, if you follow the rules below, you can create a natural chord progression.

• Do not start with a dominant (Ⅴ7、Ⅶm7-5)
• Do not progress from “substitute code” to “three code” with the same function
• Ends with a tonic chord (ⅠM7)

The following is a summary of the various diatonic chords by function.

Let’s actually create a chord progression!

Chord Progression Example

Here are three common chord progressions using major diatonic chords.

Example 1: Two-Five

Example 2: Canon Chord Progression

Example 3: 4-5-3-6 Chord Progression