40. The add9 Chord

Overview of the add9 Chord

This time, before learning the remaining sus chords, let's learn the "add9 chord," used in a wide range of genres, ballads of course included.
It is also a chord often used in arrangements that focus on common tones.

The number "9" may be a little unfamiliar, but like the maj"7," m"7" and sus"4" we have learned so far, it represents the distance from the root.
Before checking the sound of the chord, let's first unpack what this number "9" means.

We previously introduced a method of assigning numbers to the scale to make it easier to remember.

27. Relative Note Names (Scale Degree Names)
Preparing to give songs a sense of story. In the final sample last time, we showed that by using a certain device after repeating the royal road progression three times, the song can come to a pause and gain a sense of cadence

So far, numbers only went up to 8, but let's also program the second octave of the major scale and assign numbers to it.
For example, the C major scale looks like this.

This way, you can see which note the number "9" refers to.
As you can see, in the C major scale it is "D".
And adding the 9th to a major (triad) creates an add9 chord.
*It is rarely called "major add nine"; "add nine" is the common name.

In other words, the notes of Cadd9 are C, E, G and D.

The Sound of add9

Let's check the sound of the add9 chord.
The chord tones are played one by one, followed by the chord.

It isn't the simple brightness of a major triad, nor the bittersweet mood of a major seventh; it gives a clear, transparent impression.
It's a very beautiful sound.

Notation and Structure of add9

add9 is often written as follows.

The most common notation is as follows.

C add nine = Cadd9
F add nine = Fadd9

On the other hand, the notation Cadd2 is also occasionally seen, and it may differ depending on the instrument, such as piano or guitar.

Next, let's focus on the numbers.

2 and 9 are both D, an octave apart.
When we learned four-note chords, there was a "reverse way of thinking."

12. Four-Note Chords: Major Seventh
Understanding four-note chords. This time, we learn about four-note chords (tetrads, sevenths). Since "seventh" is the common name, we will write "seventh" from here on

With the same way of thinking, it's also good to memorize the 9th as the note a whole step above the root.
If you can picture it as seemingly far from the root but actually close, you can find the note quickly.

There also seems to be a way of thinking that treats 2 and 9 as separate things.

The Minor add9

While we're at it, let's learn the minor version too.
A lowercase "m" or "-" is often placed before "add."

If the half-step sound between 2 (M2nd) and ♭3 (m3rd) doesn't suit the mood, use the 9th above instead.

As you'll hear, this is a chord with a very bittersweet sound.
(The chord tones are played one by one, followed by the chord.)

Structure of add9

As an example, let's check the root position of the Cadd9/Cmadd9 chords on the score and the piano roll.

As described above, you can remember it as a major (minor) triad + M9th.

Using add9

Now let's actually use add9.
We'll use it with common tones in mind.

Key = C major: Am7 → G → Fadd9

In this progression, the top note rings beautifully as a common tone, and the flow is smooth.
Incorporating it into a II-V-I is also stylish.

Key = C major: Dm7 → G7 → Cadd9

It's an ending that leaves a lingering feeling of reluctance.

There are also cases where the 9th is used prominently in the melody, and an add9 chord is used to emphasize that melody.
When analyzing songs, be sure to pay attention to the melody as well.
Next time, we will learn the concept of "omit."

Frequently Asked Questions

Q1. What characterizes the sound of the add9 chord?

The add9 chord sits between the simple brightness of a major triad and the bittersweet mood of a major seventh, and is characterized by a clear, clean sound. In many genres, such as ballads and pop, people have found ways to use its beautiful sound.

Q2. What is the relationship between the 9th and the 2nd?

The 9th and the 2nd are the same note in different octaves: the 2nd lies within one octave of the root, and the 9th lies beyond one octave. In DTM, it's efficient to use them appropriately and to quickly recognize the 9th as the note a whole step above the root.

Q3. How does the minor add9 differ from the major version?

The minor add9 adds the 9th to a minor triad and is written as Cm add9 or Cm-add9. It has a more bittersweet mood than the major version and brings a different emotional nuance to a song, so you can choose between them to suit the mood.