This guide to triad quality and inversions requires a basic understanding of musical intervals. We recommend reading our guide to musical intervals if you need to learn or review this concept.
What is a Triad?
A triad is the most basic kind of chord in music. It consists of three notes:
- A root note
- A note a third above the root
- A note a fifth above the root
In other words, not just any group of three notes is a triad. The three pitches have to be able to be arranged in such a way that each note is a third apart (since a fifth is just two thirds stacked on top of each other).
Take the notes C, E, and G as an example. Do these form a triad?
They do, since the intervals are both thirds (from C to E is a major third, and from E to G is a minor third). Even if the notes were arranged differently (E, G, and C, for instance), they’d still form a triad, since they can be arranged so that all notes are a third apart.
On the other hand, think about the notes C, D, and G. They don’t form a triad, since no matter how they’re arranged they don’t form stacking thirds.
What is Quality?
Whether you’re playing through a guitar tab, practicing a tune on piano, or learning some other instrument, you’ll often find yourself dealing with chords.
On the other hand, you’ll notice that other chords like G Major sound different from these two in some way.
This difference in feel has a technical name: quality. Quality refers to the makeup of a chord relative to the root note.
Triads can be grouped into one of four qualities: major, minor, diminished, or augmented. Let’s take a look at each of these in further detail, and look at the music theory behind musical quality in triads.
The major triad is, in most types of music, the most common type. If you remember, a triad is composed of a root note, a third, and a fifth.
In triads of the major quality, these intervals above the root are specifically a major third and a perfect fifth. If you’re unfamiliar with these terms or just need to brush up, see our guide to musical intervals.
Building a Major Triad
Let’s look at a specific example of a major triad: C Major.
We can see that the notes in this triad are, from bottom to top, C, E, and G. But why is this?
Well, we know that the root note has to be C (it’s a C Major chord). That’s our starting point. Above this root note, we must find a major third and a perfect fifth.
A major third (four semitones) above C is E, which gives us the second note of the triad.
A perfect fifth (seven semitones) above C is G, which will be the top note.
Thus, we find that a C Major triad consists of a C, E, and G.
While we used this easy example in the key of C, this rule applies to any note in the musical scale.
Remember that triads of a specific quality always have the same exact inter-note relations, so regardless of what pitch you’re starting on you’ll always need to find a major third and perfect fifth to create a major triad.
Using the Major Scale to Find a Major Triad
When constructing a major triad, it may be easier to think of it in terms of the major scale than in terms of intervals.
Think about this: If you wanted to know what notes were in a C Major triad, you could use the method described above.
If, instead, you looked at the C Major scale and took the first, third, and fifth notes, you would have find the same notes.
This method works with any root note. Take the first, third, and fifth notes of that key’s major scale and you’ve found the major triad for that key.
Minor triads are the second most common type, and are most easily found by dropping the third of the major triad a semitone.
Building a Minor Triad
Let’s look once more at the C Major triad, composed of C, E, and G. If we drop the third (E) a semitone, it becomes Eb. We can leave the other two notes unchanged.
We find, then, that the C minor triad is made up of the notes C, Eb, and G.
This rule applies to all triads: take the major, lower the third a half-step (semitone), and you’ll have the minor triad of the same key.
Using Intervals to Find a Minor Triad
Another way to find the notes in a minor triad is to use intervals, as we did with the major. A triad of minor quality is made up of the root, a minor third (three semitones), and a perfect fifth (seven semitones).
Using C as the root note, we still end up with C, Eb, and G. This makes perfect sense because the root note and perfect fifth remain unchanged from the major triad; the only difference is a shift from a major third to a minor third, which is synonymous with dropping the third a half-step.
As another example, let’s find an E minor triad. We know that E is the root note, but what are the other two notes?
A minor third above E is G, and a perfect fifth above E is B. Thus, we find that the E minor chord uses an E, G, and B.
Using the Minor Scale to Find a Minor Triad
Instead of dropping the third of the major triad or using intervals to find the minor, you can take the first, third, and fifth notes of the minor scale.
As you can see, taking these three notes of the C minor scale leads us to the same result: a C minor triad is made up of a C, Eb, and G.
Diminished triads are certainly less common than major and minor-quality triads, but they’re important nonetheless.
Building a Diminished Triad
The easiest way to find the notes of a diminished triad is to lower the third and fifth of its respective major triad a half-step each.
To look at it differently, the diminished triad is the same as a minor triad with the fifth lowered a semitone.
Using C as our root note once again, let’s find the C diminished triad.
Lowering the third of the C Major triad (E) a half-step gives us Eb. Dropping the fifth (G) a semitone, we get Gb. Therefore, the C diminished triad is composed of a C, Eb, and Gb.
Using Intervals to Find a Diminished Triad
As with any other triad quality, you can also use intervals to find the notes in a diminished triad.
A diminished triad is created by a root note, minor third (three semitones), and diminished fifth (six semitones).
Three semitones above C is Eb and six semitones above it is Gb, so we know that these are the three notes in a C diminished chord.
If we used A instead as the root note, we’d find that an A diminished triad has an A, C (minor third), and Eb (diminished fifth).
Last but not least, we have the augmented triad. This chord is relatively rare in popular music, but it does turn up from time to time.
Building an Augmented Triad
The augmented triad is most easily found by raising the fifth of its respective major triad one half-step.
In other words, to find a C Augmented triad, you could simply take a C Major chord and raise the G to a G#, leaving the other two notes unchanged.
Using Intervals to Find an Augmented Triad
Using the interval-based approach to find the notes in a given augmented triad is also an effective method.
In terms of intervals, an augmented chord is made up of a root, major third (four semitones), and augmented fifth (eight semitones).
Using C as our root note, we find that a major third above it is E, and an augmented fifth above it is G#.
If we wanted to, instead, find an F# Augmented chord, we’d follow the same exact process. Our root note is F#. A major third above that is A#, and an augmented fifth above it is Cx (C double-sharp, which is enharmonic with D).
Regardless of your starting point, the augmented chord can always be found using these intervals in relation to the root note.
Triad Qualities Chart
|Quality||Intervals Above Root||Example|
|Major||Major Third, Perfect Fifth||C, E, G|
|Minor||Minor Third, Perfect Fifth||C, Eb, G|
|Diminished||Minor Third, Diminished Fifth||C, Eb, Gb|
|Augmented||Major Third, Augmented Fifth||C, E, G#|
What is an inversion?
An inversion is when you change the order of notes in a triad. For instance, a root (default) position C Major triad has C on the bottom, E in the middle, and G on the top.
You could invert this by moving C to the top. Now E is on the bottom, G is in the middle, and C is on top.
While we used a major triad in this example, triads of any quality can be inverted in the same way. In the example below, we inverted the F diminished chord.
Why do inversions matter?
Triad inversions create unique sounds that can’t be achieved using only root position triads. When the bass note is changed, the emphasis shifts accordingly.
Listen to the example below for a better idea of how this works; it’s a recording of the C Major triad in root position, first inversion, and second inversion (which we’ll cover next).
What are the triad inversions?
Since there are three different notes in a triad, there are three primary ways it can be arranged: root position, first inversion, and second inversion.
Root position is what we’ve been using so far in the examples: A chord is in root position when the root note is in the bass.
Think about a G Major triad: It has the notes G, B, and D.
When the notes are arranged in this order, from bottom to top, we have a G Major triad in root position.
A first inversion triad exists when the third is in the bass. Going back to the example of G Major, a first inversion triad would have, from bottom to top, B, D, and G.
To find the first inversion of a triad, just take the root position and move the root note to the top. With the G Major, we simply move the G to the top, like so:
The second inversion takes this process one step further. To find the second inversion of a triad, move the bass note of the first inversion to the top.
Taking the first inversion of G Major (B, D, G), we move B to the top. Doing so, we find that the second inversion G Major chord is structured, from bottom to top, D, G, B.
Chart of Inversions (C Major Triad)
With an understanding of the four triad qualities and triad inversions, you’ll be able to better understand more complex concepts like seventh chords.
Additionally, you can add these chord qualities to your music and experiment with them in different situations.
While you’ve almost certainly used major and minor chords before, there’s a good chance you haven’t tried, or even known about, diminished and augmented chords. They provide unique and interesting sounds that make for fascinating chord progressions when used correctly.