This next lesson might seem a little wordy in my attempt to make things clear. Let me know if there is anything that seems unclear.
Lesson 2:
Now that we have an understanding of the degrees of the scale and the identification of these degrees by Roman Numerals and names, we will now go on to building traditional triads using the scale degrees of the Major scale.
First, we must understand that a traditional triad is a chord comprised of 3 notes in intervals of 3rds. The combination of 3rds (Major or minor) will give a triad a distinct quality.
Let us begin by using the C major scale as our example.
Lets start with the note C, the first scale degree/Tonic.
Because we are using C as the foundation to build our Triad, the note C will function and be identified as the "Root" of the chord.
After establishing the note C as our root now we need two more notes and in intervals of 3rds. Therefore, our next note that is a 3rd above C would be E and our final note a 3rd above E is G.
So, our traid build on the first scale degree of C Major will be:
C-E-G
If you examine the types of 3rds used you will find that from C to E is a Major 3rd and from E to G is a minor third. You will also notice that from C to G is a Perfect 5th. This combination of intervals gives us the quality of a Major chord and that is why the first scale degree is a upper case Roman Numeral "I". The Upper case Roman numeral signifies that the quality of the chord is Major.
So, the pattern for building a major chord is making sure you have a Major 3rd with a minor 3rd stacked on top. C to E(Major 3rd), E to G (minor 3rd).
Our next chord will be built on the second scale degree (Supertonic) of the C major scale. Therefore, the note D will be the "root" of our chord. Following the previous example we will again need two more notes to complete our Triad and they must be in intervals of 3rds.
The result will be:
D-F-A
In examining our chord, this time you should notice a difference. We now have a minor 3rd with a Major 3rd stacked on top. D to F(minor 3rd), F to A (Major 3rd).
This pattern gives this the sound quality for a minor chord.
I have included an attachment that includes the C major scale. The attachment inclues the two above examples. I would like for you to build triads on the other scale degrees of the C Major scale and pay attention to the sound quality of each chord. Right now, I don't want you to worry to identify if the chord is a Major chord or otherwise. We will go over that even more once you have completed the exercise. The exercise may be a little easy but I will be a good opener to start things.