What is a diatonic chord? 7 easy-to-use codes in the key

A diatonic chord is a chord created by layering only the notes included in one scale. It lets you see candidates that fit naturally in the key, giving you a starting point for creating chord progressions.

7 chords in C major

C, D minor, E minor, F, G, A minor, B diminished. It can be made by layering three notes from each note of the C major scale, one at a time.

Express in degrees

To explain the role even if the key changes, we will use Roman numerals: I, ii, iii, IV, V, vi, vii°. Uppercase letters are major, lowercase letters are minor.

Tonic

I, vi, and sometimes iii are groups that tend to be stable. It is used at the beginning or end of a song, or at a calming place. C major is represented by C and A minor.

Subdominant

IV and ii have the role of slightly moving from stability. This is a chord that can be easily expanded and connected to a dominant. In C major, it's F and D minor.

Dominant

V and vii° create a sense of tension and have a sound that makes you want to go back to the tonic. In C major, it's G and B diminished.

Chord progression basics

If you create a flow that starts with the tonic, moves through the subdominant, tenses up with the dominant, and returns to the tonic, it will become more coherent. C→F→G→C is an easy-to-understand example.

Chords other than diatonic can also be used. It will be easier to understand the meaning of the changes by first getting a feel for the role of the seven in the key, and then adding borrowed chords and secondary dominants.