An Easy Way to Understand Harmony | Part I: Major Scale & Diatonic Chords

Whether you’re writing or analyzing music, a basic understanding of diatonic harmony will make a serious impact on how you digest and/or produce a song. Once you grasp the fundamentals of how chords are built and combined to make progressions, learning and/or writing new songs will become a breeze. Follow the steps below, slowly.

1. Build a Scale for the Song’s Key

The major scale is the foundation of harmony, in which everything can be related back to in music. It is made up of a specific formula using half steps and whole steps:

Whole | Whole | Half | Whole | Whole | Whole | Half

‘C’ major is arguably the easiest key to demonstrate this, as it uses all natural notes (no sharps or flats). If we start on C and use the major-scale formula, we get:

C | D | E | F | G |A | B | C

C to D is a Whole step; D to E is a Whole step; E to F is a Half step; F to G is a Whole step; G to A is a Whole step; A to B is a Whole step; B to C is a Half step

2. Build Triads for Each Note in the Scale

Triads are built in thirds, or every other note. Take each note in the scale and build its triad. This will give you the root, 3rd, and 5th of each chord available (diatonically) in the key:

C – E – G: C major triad

D – F – A: D minor triad

E – G – B: E minor triad

F – A – C: F major triad

G – B – D: G major triad

A – C – E: A minor triad

B – D – F: B diminished triad

The 3rd (middle note here) is what determines if a chord is major or minor. If the 3rd is two whole steps away from the root, the chord is major. If the 3rd is one and a half steps away from the root, the chord is minor.

Now, you have all the chords that ‘work’ in the key of C major (aka Diatonic chords). Experiment with various progressions using any number of these chords in any order.

3. Assign Numbers to Each Chord in the Scale to Make Universal

You can repeat steps 1 and 2 in other keys to determine chords that ‘work’ in all major keys. Keep in mind: the formulas will be the same for any major key. Meaning, the first note in the scale will always produce a major chord; the second a minor chord; the third a minor chord; the fourth a major chord, etc. Since this formula of chords is identical across all major keys, we can assign a number (using Roman Numerals) to each triad:

I | ii | iii | IV | V | vi | vii°

Pro Tip: Take time to memorize all your major key signatures, which will allow you to know what each chord number relates back to in every key without having to tediously write out all notes in that key using the Whole/Half formula.

Thinking of chords numerically like this allows us to do accomplish many things:

  • Analyze songs and observe common chord progressions

  • Transpose chord progressions from one key to another seamlessly

  • Focus on the sound, vibe, and color of specific chord progressions

  • Identify familiar chord progression easier when learning a song

  • Write music more efficiently

There are, of course, songs that use more complex harmonies and techniques. However, it is important to allow yourself to fully digest these basics before moving on to the next level of harmony. Consider taking the following steps to build-up your harmonic confidence:

1. Review All Musical Intervals

2. Review Circle of Fourths/Fifths + Key Signatures

3. Memorize All Key Signatures and Major Scales

4. Memorize Chord Scale Formula For Major Keys

5. Analyze and Write Chord Progressions Using Diatonic Chords

6. Begin Training Your Ear to Identify Common Chord Progressions

Some common diatonic chord progressions across all genres are:

I vi V IV

ii V I

I IV V

I vi ii V

I IV vi V

IV I V I

LessonsMichael ZdebComment