Understanding Triads (Chords)

A chord can be defined as a group of two or more harmonizing notes.

The most basic and common formation of a chord, a triad, is a group of three harmonizing notes in which an interval of a third and an interval of a fifth is played above the root note.

Now, there are two different types of thirds and two different types of fifths which are used when constructing triads.

The first type of third we need to know about is called a Major third. A Major third is constructed by adding two consecutive whole steps above or below a given note.

WholeStep_CD.png

For example, knowing that C to D is a whole step,

WholeStep_DE.png

and D to E is also a whole step,

MajorThird_CE.png

then C to E having been two consecutive whole steps is a Major third.

A minor third, on the other hand is constructed by adding a half step and a whole step above or below a given note.

HalfStep_EF.png

Again, knowing that E to F is a half step,

WholeStep_FG.png

and F to G is a whole step,

MinorThird_EG.png

then E to G, having been a half step followed by a whole step, is a minor third.

The first type of fifth that we need to know about is called a Perfect fifth. A Perfect fifth fifth is constructed by adding a Major third and a minor third above or below a given note.

MajorThird_CE.png

We just learned that C to E is a Major third,

MinorThird_EG.png

and E to G is a minor third.

PerfectFifth_CG.png

Therefore, C to G, having been a Major third followed by a minor third is a Perfect fifth.

The second type of fifth is known as a diminished fifth. A diminished fifth is constructed by adding two consecutive minor thirds above or below a given note.

MinorThird_BD.png

If we know that B to D is a minor third,

MinorThird_DF.png

and E to and D to F is also a minor third,

DiminishedFifth_BF.png

then B to F, having been two consecutive minor thirds is therefore a diminished fifth.

It’s worth mentioning that another even easier way of thinking about diminished fifths is that they are the same as perfect fifths just lowered by one half step.

PerfectFifth_BFsharp.png
DiminishedFifth_BF.png

A Major triad is formed by adding a Major third and a Perfect fifth above the same note.

MajorThird_CE.png

By playing a Major third above the note C,

PerfectFifth_CG.png

along with a Perfect fifth above the note C,

CMajorTriad.png

we will have constructed a C Major triad - C, E, and G.

Another way to construct a C Major triad is by combining the first, third, and fifth scale degrees of a C Major scale.

CMajorTriadSTAFF.png

Here we can see that the first scale degree is the note C, the third scale degree is the note E, and the fifth is G.

A minor triad is formed by adding a minor third and a Perfect fifth above the same note.

MinorThird_DF_2.png

By playing a minor third above the note D,

PerfectFifth_DA.png

along with a Perfect fifth above the note D,

DminorTriad.png

we will have constructed a D minor triad - D, F, and A.

Another way to construct a D Major triad is by combining the first, third, and fifth scale degrees of a D minor scale.

DminorTriadSTAFF.png

Here we can see that the first scale degree is the note D, the third scale degree is the note F, and the fifth is A.

A diminished triad is formed by adding a minor third and a diminished fifth above the same note.

MinorThird_BD.png

We already know that the note D is a minor third away from B,

DiminishedFifth_BF.png

and F is a diminished F away.

BdiminishedTriad.png

By combining these three notes we will be playing a B diminished triad.

Each note of a Major scale can be considered the root note of a different triad.

For example, triads built on the first, fourth, and fifth scale degrees will always be Major.

Staff_MajorTriads.png

Triads built on the second, third, and sixth scale degrees will always be minor.

Staff_minorTriads.png

And a triad built on the seventh scale degree is diminished.

Staff_diminishedTriads.png