54. The Minor Two-Five (II-V)

Using Chords Other Than the Three Primary Minor Chords

This time, we will check things using the same steps as with major and learn how to use chords other than the three primary minor chords.
In fact, this lesson also leads to one way of naturally incorporating "VIIdim" and "VIIm7♭5," the hard-to-use seventh diatonic chords of major, into songs.
In the first half of "Fly Me to the Moon (In Other Words)," which we showed in "25. Using Degree Names (Four-Note Chords) and the Existence of Non-Diatonic Chords," they were incorporated in a strong, natural flow.

IIdim (IIm7b5) as a Substitute for IVm (IVm7)

So far we have introduced cadences formed only with the three primary chords, but of course songs in minor keys don't use only those three chords.

With major, we said that "other chords can also have functions similar to these," and the idea is the same in minor keys: other chords can replace them, meaning they may be usable as "substitute chords."

With major, we checked this by putting an SD (substitute) chord in the SD position of the typical cadence "T → SD → D → T," which moves from stability to the next development and then through tension to a sense of relief.

Example) Key = C major

• C → F → G7 → C

• C → Dm7 → G7 → C

The flow of the story, moving from stability to the next development and then through tension to a sense of relief, doesn't sound very different.
In other words, IIm7 could be used as a substitute for SD.

And if you listen while focusing on the root notes, you will probably feel that the latter, which is a strong progression, has a more powerful chord progression.
Let's try this idea in minor as well.
We will check it based on the minor T → SD → D → T covered in Lesson 52.

*Since all of these are chords built on the tonic, subdominant and dominant, they are sometimes written using only T, SD (S) and D, but this time too we will write them as in the image above for clarity.

First, where is "II" in a minor key?

It's the part outlined in blue in each table.
Let's actually incorporate it.
We will check it in the key of C minor.

T → SD → D → T

• Tm → SDm → Dm → Tm / Cm → Fm7 → Gm7 → Cm

Now, in the SDm position, let's use IIm7b5, which is often used as a substitute chord.

• Tm → SDm (substitute) → Dm → Tm / Cm → Dm7b5 → Gm7 → Cm

It isn't bad, but a slightly ambiguous feeling remains.
Next, let's change the second half to a "stronger" flow.

T → SD → D → T

• Tm → SDm → D → Tm / Cm → Fm7 → G7 → Cm

• Tm → SDm (substitute) → D → Tm / Cm → Dm7b5 → G7 → Cm

You can feel a stronger sense of progression.
The key also feels easier to grasp.
When you analyze ordinary songs, you will probably see this flow more often.

The strong progression SD → D → T in the second half feels even stronger.
When you find this flow while analyzing songs, be sure to pay attention to it.

Frequently Asked Questions

Q1. What is a two-five progression in a minor key?

It refers to a flow in a minor key from the chord on the II degree (such as Dm7♭5) to the chord on the V degree (such as G7). This progression strengthens the sense of resolution to the tonic (I) and gives the chord progression strength and naturalness.

Q2. Please explain the substitute relationship between IIm7♭5 and IVm.

IIm7♭5 functions as a substitute chord with a subdominant function and can be used in the position of IVm. It plays the same functional role while adding a different color, creating a more refined chord progression.

Q3. Is this progression often used in actual songs?

Yes, it can be found in many genres, such as jazz, pop and anime songs. It is common for this progression to be incorporated into the strong T → SD → D → T flow, making the key easy to grasp and giving listeners a sense of stability.