Triads & Major Chords / Music Theory Lesson

Author: sleepfreaks

Understanding what Chords are

We will finally begin taking a look at chords.
This is the first step in real song writing.

The information you learn in music theory begins to all come together.

By using the scales and intervals we learned about,
we can begin to learn how to make chords.


When you hear “chord = harmony”, this is because it is a sound that is created when notes of different pitches are layered together.

With intervals, we learned that 2 notes can create a musical sound together.
However, this can be thought of as a type of simplified chord as well.

Major Chords made out of 3 notes

Lets first take a look at triads which are made up of 3 notes.

We will take a look at the bright sounding major chord first.

Below we have the C major chord.
※ The chord will play after the individual notes are played

Major chords are often depicted as the following:


The most common way you may see it written is as

  • C major chord = C
  • D major chord = D

Lets take a look on notation and the piano roll.



Before looking at intervals, lets learn about what root is as well.
The root refers to the base note of the harmony.

The basic contents making up a C major chord is C, E, and G.
In this case, the “C” is the root, with E and G stacked above it.

This means the letter designated to the chord is also it’s root note.

C Major chord


D Major chord


Lets take a look at the D major chord as well.
Once again, the chord will play after the individual notes are played.

These are the notes that make up the chord.



Rules when Creating Major Chords

We learned how to put together a C and D major chord above.

However, does that mean you must remember how to make every single major chord?
There must be some sort of rule to this.

Lets compare the C major chord to the D major chord.



After selecting the D major chord, lets move the root note of D down to C.


By doing so, both chords become C major chords.
This means that the relative distance of the notes on top of the root are the same.

We’ll take a look at how a major chord is constructed,
and how notes are layered onto the root note.



We have prepared intervals on the right of the C major chord.


With C as the root, lets extend E and G above it to the right.
With the root C as 1, the notes that are a “M3rd above” and “P5th above” make up the C major chord.

Lets try this out this knowledge for the D major chord as well.


We can make a D major chord by adding the notes that are a “M3rd above” and “P5th above” the root.
This same rule applied to the C major chord.

In this case, we can see that a
major chord is made up of the “root” + “M3rd above” + “P5th above”.

At this point lets take a look back on “scale degree” as well.


The notes are “1 + 3 + 5”.

If making an “E major chord”, first think of the E major scale.


By layering the 1/3/5 of the E major scale, you can make the E major chord.

In conclusion:

The basic structure of a major chord:

  • In intervals: ” R + M3rd + P5th ”
    ✴︎R refers to root
  • In scale degrees : ” 1 + 3 + 5 “

This is a rather simple concept.
Next time, we will use this information and take a look at minor chords!

Article Writer: Kazuma Itoh

講師 伊藤
After moving to the USA at 18 years of age with a scholarship from Berklee, he completed a 4 year study focused on song writing and arranging there.
Using this knowledge, he works across a variety of fields from pop music, film music, and more.