Lesson 20: Chords of a Major Key (大調中的和弦) - Part 1

The scale of a major key consists of 7 notes. For example, in the key of C, those 7 notes are: C, D, E, F, G, A, and B. And we have learnt in Lesson 19, a triad is made up of 3 notes are stacked in thirds.

In other words, we can derive 7 distinct triads from a major key scale, with the root of each triad being the different scale degrees. Here is the example in the key of C:

• Starting with 1 (C): C - E - G
• Starting with 2 (D): D- F - A
• Starting with 3 (E): E - G - B
• Starting with 4 (F): F - A - C
• Starting with 5 (G): G - B - D
• Starting with 6 (A): A - C - E
• Starting with 7 (B): B - D - F

By looking at the intervals between the notes in each of these triad, one can easy figure out the quality of the above chords (review Lesson 19 if necessary):

• C - E - G: C Major, or C
• D- F - A: D minor, or Dm
• E - G - B: E minor, or Em
• F - A - C: F Major, or F
• G - B - D: G Major, or G
• A - C - E: A minor, or Am
• B - D - F: B diminished, or Bdim

To summarize, the pattern for the triads in the key of C is as follows:

1M 2m 3m 4M 5M 6m 7dim

In fact, the same pattern applies for all 12 keys!! That means, in the key of D, the triads that can be derived from the key are: D, Em, F#m, G, A, Bm, C#dim. Try to verify that for yourself!

Lesson 19: Chords(和弦) and Triads(三和音)

In music theory, a chord(和弦) is a general term that is defined as a set of two or more notes that sound simultaneously. The chords that we commonly see in worship songs can be further categorized into triads (三和音) and seventh chords (七和弦). Occasionally, we also come across chords that do not belong to either of the aforementioned categories. We will focus on the triads in this lesson, and learn about seventh chords in the next.

As the name suggests, a triad is a chord that consists of 3 notes. Also, they are stacked in thirds (i.e. the interval between the first and second note, and the interval between the second and third note are both 3rds, either major or minor). When stacked in 3rds, the 3 notes in a triad are called (from bottom to top):

• the root [R],
• the third [3], which can be at an interval of major or minor 3rd above the root
• and the fifth [5], which can be at an interval of diminished, perfect, or augmented above the root. (this will be illustrated shortly)

Since there are two possibilities for the interval between the root and the third (major or minor 3rd) and there are two possibilites for the interval between the third and the fifth (major or minor 3rd), by permutation, we can deduce that there can be 4 possibilities for triads. We call these the quality of the triads. Here are the 4 different qualities: major, minor, diminished, and augmented.

Major triad: R-3-5.

• It consists of a Major 3rd from R to 3 and a minor 3rd from 3 to 5.
• This is also commonly known as the "major chord".
• It is usually written with just the capital letter of the root, e.g. C, F.
• Example: C-E-G

Minor triad: R-b3-5.

• It consists of a minor 3rd from R to b3 and a Major 3rd from b3 to 5.
• This is also commonly known as the "minor chord".
• It is usually written with the capital letter of the root followed by an "m" or "-", e.g. Cm, F-. It is also sometimes written with the small letter of the root, e.g. c, f (less commonly seen in worship music).
• Example: C-bE-G

Diminished triad: R-b3-b5.

• It consists of a minor 3rd from R to b3 and another minor 3rd from b3 to b5.
• The diminished triad contains and diminished 5th above the root.
• It is usually written with the capital letter of the root followed by "dim" or "º", e.g. Cdim, Fº.
• Example: C-bE-bG

Augmented triad: R-3-#5.

• It consists of a Major 3rd from R to 3 and another Major 3rd from 3 to #5.
• The augmented triad contains and augmented 5th above the root.
• It is usually written with the capital letter of the root followed by "aug" or "+", e.g. Caug, F+.
• Example: C-E-#G

Each of the above triads have a distinct mood to it, regardless of what the root note is. Try playing the above examples on the piano to hear the difference. Once you are familiar with the examples, try to play these triads with different root notes.