This free tutorial will introduce the idea of triads, what they are, what the use of stacked thirds is, and introduce the different triad qualities. This will then be demonstrated by constructing a major triad. The tutorial for silver members will then continue this by demonstrating the construction of the three remaining triad types with examples and summarize this process.

Triads and what they are

Triads are the foundational building blocks of harmony in Western music. They are specific combinations of three pitches.

Triads are formed by stacking two intervals of a third on top of a root note. This results in intervals for triads (compared to the root note) of root, third, and fifth,

Depending on the quality of these thirds, we get different types of triads: major, minor, diminished, and augmented.

There are two types of thirds, major thirds and minor thirds.

A minor third (m3) spans 3 semitones – eg: C to E♭

A major third (M3) spans four semitones eg: C to E.

Since we have a combination of two thirds which can be either major or minor, we can have four different combinations of two of these. We can have

• M3 m3
• M3 M3
• M3 m3
• M3 M3

These four combinations correspond to the four triad qualities

• Major
• Minor
• Diminished
• Augmented

Stacking thirds means putting one third on top of another, for example a Major third above the root note, then a minor third above that note, M3 + m3.

Major Triads

Major triads are constructed by stacking a Major third and a minor third.

M3 + m3

So, for the example of a C major triad we start with the root note, C. We find the note a Major third (4 semitones) above that, which is an E. Then we find the note that is a minor third (3 semitones) above the E, which is a G.

This results in the pitches for our C Major triad being

C – E – G

This same process applies for every major triad starting on any root note.

We can note that the intervals above the root are

Root – major third – perfect fifth

Major triads are generally considered to sound bright, stable, and consonant.

If you would like to see how the other triads – minor, diminished, and Augmented – are constructed and a summary of the different triad qualities and their stacked third formula please sign up for the silver membership.