Lesson 5 | Diatonic Harmony

In this lesson I would like to share with you a very fundamental understanding of how musicians typically think of chords and chord progressions. Diatonic harmony was a real eye opener for me and it really provides the foundations for so much musical knowledge. Its really not that complex and yet again it’s something that’s based off the major scale.

What are Diatonic Chords?

Diatonic chords are the chords that are derived from the notes of a key. You should think of diatonic chords as a family of chords all tied to one another by the notes of a key. We’ve determined that the major scale has seven notes and that each key contains seven different notes.

Therefore, it is possible to build a chord on each of the seven notes in every key.

Each note of the key acts as a root note for a chord, therefore each key has seven basic diatonic chords. In practice we use uppercase roman numerals to indicate major chords and lowercase to indicate minor chords.

Naming the Diatonic Chords with Roman Numerals

By now you’ll understand that the notes of the major scale are numbered  1, 2, 3, 4, 5, 6, and 7. We call these scale degrees.

When we discuss diatonic chords we can name them with Roman numerals. This becomes very handy, especially amongst session musicians in the Nashville studio scene. Rather then writing out chord names, they use roman numerals to illustrate chord charts.

Check out the seven chords in the key of C: