If you’re new to jazz, you’ve probably heard musicians talk about the “ii–V–I” progression over and over again. It comes up in rehearsals, lessons, jam sessions, and nearly every jazz standard — often without much explanation.

So what is a ii–V–I, and why is it so important?

In this post, we’ll break it down in a clear, practical way so you can finally understand what those numbers mean and how they help you improvise with more confidence.

What Does “ii–V” Actually Mean?

The ii–V refers to scale degrees, not specific chord names.

ii means the chord built on the second note of a scale
V means the chord built on the fifth note of a scale

Jazz musicians use numbers because they describe function, not just chord labels. Once you understand the numbers, you can recognize the progression in any key.

Example: ii–V in C Major

Let’s start with the C major scale:

C – D – E – F – G – A – B – C

Building the ii Chord

The second note of the scale is D.
If we stack notes from the C major scale on D, we get:

D – F – A – C

This is a D minor 7 chord — the ii chord.

Building the V Chord

The fifth note of the scale is G.
Stacking scale notes on G gives us:

G – B – D – F

This is a G7 chord — the V chord.

Why the ii–V Is So Important in Jazz

The ii–V progression creates forward motion.

When the ii moves to the V, it creates tension. That tension naturally wants to resolve to the I chord, also called the tonic. This sense of movement and resolution is one of the foundations of jazz harmony.

Once you learn to hear and recognize ii–V progressions, the music starts to make a lot more sense.

What This Means for Improvisation

Here’s the key simplification that helps many players:

👉 In a major key, you can use the major scale of the I chord over the ii–V.

In C major:

D minor 7 uses notes from the C major scale
G7 uses notes from the C major scale

Because both chords come from the same parent scale, the C major scale works over both chords. This makes improvisation feel far less overwhelming, especially when you’re starting out.

Seeing the Connection Between Chords and Scales

All three chords in a ii–V–I come from the same scale:

I chord (C major 7): C – E – G – B
ii chord (D minor 7): D – F – A – C
V chord (G7): G – B – D – F

Every note in each chord comes directly from the C major scale. Understanding this connection helps you choose scales faster and play with more confidence.

Important Note About Major vs. Minor

This approach works when:

The key is major
The I chord is major

Minor ii–V progressions follow different rules and use different scales. That’s an important topic — just one we’ll save for another day.

Another Example: ii–V in F Major

The F major scale:

F – G – A – B♭ – C – D – E – F

From this scale, we get:

I chord: F – A – C – E (F major 7)
ii chord: G – B♭ – D – F (G minor 7)
V chord: C – E – G – B♭ (C7)

Once again, all the chords come from the same parent scale: F major.

How to Quickly Find the Right Scale

When you see a ii–V in music:

The ii and V chords always appear together
The correct scale is the major scale one note below the ii chord

For example:

G minor 7 → C7
One note below G is F
Use the F major scale

Final Thoughts

The ii–V–I isn’t complicated — it just isn’t always explained clearly.

Once you understand how scale degrees, chords, and keys are connected, improvisation becomes more intuitive. You spend less time guessing and more time listening, shaping phrases, and making music.

If this explanation helped you, be sure to subscribe to the Improv Insight, our weekly newsletter.

Want an easy practice system?

I’ve put together an eBook that teaches these concepts through different exercises written out with PDFs and backing tracks for each individual instrument.

👉 Download the eBook here

As always — happy practicing!

What Is a ii–V–I in Jazz? A Simple Explanation for Beginners