The last couple installments of our little discussion of the nature of chords dealt with triads. We learned what they are, and we learned that many of these three-note chords originate from our major scales. If you didn’t catch the last two posts titled “Where Do Chords Come From? (Part 1), (Part 2) I suggest reading them as a precursor to this lesson. Right now let’s find out more about triads, exactly what their construction looks like, and how to go about naming them.
Triads are three-note chords, some types of which are derived from the major scale, and one type which is not. The three notes of a triad are referred to as the chord’s root, the third of the chord, and the fifth of the chord. These notes are called “chord-tones.” The root of the chord is the note which names the chord. The other notes in the triad give us information about what type of chord it is. Triads can be major, minor, diminished or augmented. Major and minor are the types most commonly used, especially in rock and roll, followed by diminished chords and then augmented chords. We determine the chords type by measuring the distances (or intervals) between the three chord-tones. Below are diagrams showing the distances between chord-tones for each type of triad:
ROOT________4 half-steps_________THIRD________3 half-steps_________FIFTH
ROOT________3 half-steps_____(b)THIRD_________4 half-steps__________FIFTH
Look at the above diagram. In both the major and minor triads, the fifth of the chord is seven half-steps higher than the root. It is the middle note, the third of the chord, which changes placement to determine the difference between these two types of chords. In the minor triad the third is one half-step lower, or closer to the root. Therefor we consider the minor triad to have a “flatted third.” (In music we compare everything to the major when determining how to name note-relationships.)
Here are the other two types of triads:
ROOT________3 half-steps_____(b)THIRD______3 half-steps_______(b)FIFTH
ROOT________4 half-steps_________THIRD___________4 half-steps___________(#)FIFTH
The third of the diminished chord has the same placement in relation to the root as it does in the minor chord. Therefore, diminished chords have flatted thirds also. By the same logic, the diminished triad has a “flatted fifth” as well, and the augmented triad has a “sharped fifth.” This will be easier to see in the next diagram, which is much more visual:
The diagram above is a great example of a way to develop a mental picture in your mind for what a triad “looks like.” Each of the horizontal grids are marked by vertical lines which represent the notes of the chromatic scale. The spaces between the lines represent half-steps. The root of the triad is represented by the letter “R,” at the left end of the grid, and the octave of the root by the “R” at the right end if the grid. The appropriate thirds and fifths are marked as well. This lends a graphic representation of the chord in visual space.
Exercise: Pick a root at random, and practice “spelling” each type of triad that can be associated with it. By “spell,” we mean figure out what the notes would be in that triad. For example, for the root “D,” you would do the following.
- D Major: Root = D, third = F#, fifth = A
- D minor: Root = D, (b)third = F, fifth = A
- D diminished: Root = D, (b)third = F, (b)fifth = Ab
- D Augmented: Root = D, third = F#, (#)fifth = A#
You can practice writing it down, and once you get good at this just try doing it in your head.
Chords in the key of C Major:
In a previous post, “Where Do Chords Come From? (Part 2)” we found and listed all the triads we can build using the notes in the key of C Major. We have now learned the information we needed to name all the triads we found. Let’s look at them:
C-E-G: The root of this triad is “C.” The third, (E) is two whole-steps (4 half-steps) up from the root. That is, it is in the spot where the third would be in a major triad. The distance between the third, (E) and the fifth, (G) is three half-steps. So this triad follows exactly the picture of a major triad which we examined in our diagrams above. Therefore the name the first triad in the key of C is “C Major”.
D-F-A: The root of this triad is “D.” The third, (F) is three half-steps up from the root. This follows the formula we learned above for building a minor triad, and it means this triad contains a flatted third. The distance between the flatted third, (F) and the fifth of this triad is two whole-steps (4 half-steps) and this also follows our formula for building a minor triad. Therefore the name of the second triad in the key of C is “D minor.”
Following this process with the other triads we can build from the notes in the key of C, we get the following chords:
- E-G-B: E minor
- F-A-C: F Major
- G-B-D: G Major
- A-C-E: A minor
- B-D-F: B diminished
So the seven triads or chords which come from the key of C Major are:
- C Major,
- D minor,
- E minor,
- F Major,
- G Major,
- A minor
- B diminished.
This is information is really important. Even before we feel completely comfortable spelling triads, we can use this knowledge to give us some real important insights into improvisation and composition. The next lesson will talk a lot about this.