Now that we have taken a look at a few scales and the relationship between the underlying notes, I would like to take a minute to discuss basic chord formation using these scales.
A Chord is a combination of notes derived from a certain scale combined together in order to bring out the underlying harmony of the particular scale. The most basic form of chords is called a Triad, which is created by using 3 notes of a scale in order to bring out the basic harmony between this trio of notes. A triad is most commonly formed by starting on the root note of a scale, adding the 3rd scale interval (major or minor) note, and finally adding the 5th scale interval (major or minor) note in order to complete the chord.
As we addressed earlier, scales are made up of 12 semitones or half steps from start to end note. Now we will take this one step further by adding the rules of determining major 3rd intervals and minor 3rd intervals. A major 3rd interval is created by any 2 notes in a scale that are 2 whole steps (or 4 half steps) apart from each other. A minor 3rd interval is any 2 notes in a scale that are 1½ whole steps (or 3 half steps) apart from each other. If we take another look at the C major scale we can demonstrate what a triad looks like using major and minor 3rds:
As we can see, there are 2 whole steps (or 4 half steps) between C and E, and 1½ whole steps (or 3 half steps) between E and G to complete our C major triad. There are 4 possible chord qualities for triads based on the relationship of the notes used to create the triad: Major, Minor, Diminished and Augmented.
There are a few specific rules to keep in mind when creating simple 3 note chords:
1. The first 3rd interval determines whether the chord will be major or minor.
2. The second 3rd interval determines whether it will be augmented or diminished.
3. Major Triads are always formed with a major 3rd followed by a minor 3rd.
4. Minor Triads are formed with a minor 3rd followed by a major 3rd.
5. Diminished Triads are formed with a minor 3rd followed by another minor 3rd.
6. Augmented Triads are formed with a major 3rd followed by another major 3rd.
Once you learn these rules, you can apply them to create any of these 4 triads on any starting key! For example, if you wanted to create an E minor triad, simply start on the key of E, go 3 half steps (or a minor 3rd) to G and 4 half steps (or a major 3rd) to B and you have your triad. As you will quickly learn, there are natural triads that are created within each scale using the step patterns in the scale starting on each individual note. Our E minor triad was formed by starting on the 3rd note of C major and applying the simple triad rules in order to create one of the minor triads within the scale. Once you start to get more comfortable with the scales, you will start to notice all of the underlying triads you can make within each scale by simply applying the step pattern rules for each specific triad.
Now that you have a basic knowledge of how to create 3 note chords, we can begin to explore the options we have within a scale to develop melody and harmony, create extended chords on top of our triads and even how to substitute one chord for another entirely. Before we move into more advanced theory, we will take a look at our 2 remaining minor scales and bring it all together.