Other Types of Chords and Their Functions
There is more to music than just Major/minor triads.
First we will examine diminished, as well as augmented chords. Then, we will examine chords that are comprised of more than three notes.
The diminished chord is built by adding an additional note to the Tritone.
Each scale has a Tritone, and each Tritone has notes that fall between the boundaries of its own notes. These can be used to build chords.
In any major key, the chord built off of the seventh scale degree will be diminished. In any minor key, the chord built off of the second scale degree will be diminished. Let’s examine this, by first using the key of C major. The notes belonging to our seven chord are colored in red.
In major, the vii° chord is diminished.
This chord is built off of the B. Below, it is in first inversion, the D being the lowest note.
Let's examine the scale starting on B, to make visualizing it easier.
Now the vii° chord is in root position.
Minor scales also include diminished chords.
In minor, the diminished chord is the ii°.
Here, you can see the two chord in root position.
Can you spot the tritone in this chord?
Let's compare the Major, minor and diminished chords.
These three types of chords contain different spacings. The major chord is the chord with the most spacing from the root. You can turn a major chord into a minor chord by lowering the third. You can then also lower the fifth to make a diminished chord.
Major
Minor
Diminished
What is a dominant seventh chord?
Below, I will diagram a C dominant seventh chord. Notice the subscript next to the Roman numeral V. This example will be based off of the F major scale.
Notice the scale degree numbers above the scale. As with our previous examples, this represents scale degrees from F. The scale degree numbers below represent our degrees from C. Our fourth note, the B♭, is the seventh note from our chord’s root note, C.
Also notice that there is a tritone between the B♭ and E. This will resolve to an A as well as an F, allowing us to resolve to our I chord.
Are all seventh chords dominant?
No. Not all seventh chords have a Tritone. Let’s examine the I maj7 chord in F major:
Other types of chords contain notes intended to color what is already there.
One good example of this is the suspension. I am going to diagram a su4 chord below, based off of the F major chord, as well as resolve it back to the I chord.
A sus2 would look like this:
Chords are named in a very logical manner.
As a musician, you will likely run into some pretty complicated chord names. But do not fear! You can always figure out how to spell a chord by examining its name.
Take a C+, the C augmented chord. We know what an augmented interval is from previous chapters. Only one interval in this chord could be altered to be augmented. It is the interval of a perfect fifth, raised one half-step. We can easily build this chord by altering that fifth in our C major chord to be one half step higher.
Next, let’s examine chords that add notes past the octave.
Up to this point, you have seen me use the designation 1 for the octave. But we can imply notes past the octave by using the numbers eight and up past that point.
The eight and one are interchangeable. Therefore, a chord that asks you to add a nine would be referring to the two, one octave up.
Can you use this logic to build a chord that adds a 13? Try it!
Next, let’s examine diminished seventh chords.
These come in two flavors: fully-diminished, and half-diminished. These tend to be the most difficult chord for students to grasp, but fear not! They are as easy and logical as the preceding examples.
A fully-diminished seventh chord has a diminished seventh added to it. Recall that the diminished interval is a half-step smaller than the minor interval. So, if we want a fully-diminished seventh chord, we want a diminished seventh interval at the top of a diminished chord. We can find this easily by using the minor scale, and altering our notes from there. Let’s use c minor.
After we find our c minor chord, let's flat the 5 to G♭ and the 7 to a B♭♭. (Yes double flats exist.)
We can even make a half-diminished 7th chord by keeping the B♭. These are represented with the ø symbol.