Building Chords from the Major Scale

Building Chords from a Scale

Play the C major scale. Let’s take a look at the harmonic possibilities in this group of notes. Harmony is simply the combination of multiple pitches. But how do we combine pitches? Do we randomly mix them together and hope they’ll sound good? That’s one way to do it. However, there is a more organized method that offers greater understanding.

Examine the notes of the C major scale, and look at their relationship on the graph that plots the notes in order of lowest pitch to highest pitch.

Basic Chord-Building Method

Most chords in popular music can be created by using a simple method of stacking notes in groups of thirds.

The most common method of creating chords from this scale is to add two more notes to each, using thirds. Consider the first note, C. To create a chord out of this note, we will start on C, skip the next tone (D) and add E. Then we’ll skip the next tone (F), and add G. This creates C-E-G. When these three notes are played together, they produce the chord C major. Comparing this to the C major scale reveals a chord made from the first, third and fifth note of the C major scale. Our next note is D. When we repeat this process, we have the configuration D-F-A.

This will also be a major chord, right? Not so fast. For the moment, let’s pretend to be in the key of D. D has two sharps: F♯ and C♯. In the key of D, a major chord would have the notes D-F♯-A. Because our D chord is constructed from notes out of C major and not the D major scale, we have to shrink the F♯ down to F to fit it into our scale. That means that instead of producing a major chord, we’ve produced a minor chord.

C Major Scale

C Major Chords

All of the remaining chords are either major chords or minor chords, with the exception of the seventh chord, B. The key of B has five sharps: F♯, C♯, G♯, D♯ and A♯. Like the D chord, the distance between the first note of this chord—B—and the third—D—has been shrunk. However, in the key of B, the fifth note is F♯. The fifth note of our B chord has also been shrunk, or diminished.

Compare the three types of chords to be sure that we understand why a chord is called major, minor or diminished. It’s all about the distance of the harmonized notes—how far away they are from their root. Take the C major chord for example:

The C Major Chord

(Major third + minor third)

C major has a major third between the root (C) and the third (E), and a perfect fifth between the root (C) and the fifth (G). That's why it's a major chord.

The D Minor Chord

(Minor third + major third)

Compare the C major to D minor:

D minor has a minor third between the root (D) and the third (F), but still a perfect fifth between the root (D) and the fifth (A).

The B Diminished Chord

(Minor third + minor third)

Finally, let's look at a diminished chord:

B diminished has a minor third between its root (B) and its third (D); but also a diminished fifth between its root (B) and its fifth (F). That's why it's a diminished chord.

These chords also sound very different from each other. The major chord sounds happy. The minor chord, with its flatted third, sounds sad. The diminished chord, with a flat third and diminished fifth, sounds restless.

Key Tasks

1) Memorize the chord qualities and Roman numerals:

…Which chord(s) are major? _______________

…Which chord(s) are minor? ______________

…Which chord(s) are diminished? _____________

2) Write out the chords that occur in the following keys: G, A, F, B♭.