Jazz Chord Progressions

The ii-V-I chord progression is the most common chord progression in jazz music and many pop songs. For many beginning guitar players, this topic can be a little bit mystifying so let’s unpack it. 

Some background on the ii-V-I progression

In every major key, there are seven chords. Regardless of which key we are in, the quality (major, minor, diminished) and the order in which they occur will never change.

Here’s an example in the key of C major. 

C, Dm, Em, F, G, Am, Bdim

As mentioned, the quality and order of these chords won’t change, so they are not exclusive to any given key, so we can begin to represent them as numbers rather than specific chords symbols:

1, 2m, 3m, 4, 5, 6m, 7dim

Now, let’s switch to the commonly used format of Roman Numerals: 

I, ii, iii, IV, V, vi, viidim 

So a 2m, 5, 1 (also written as ii, V, I) in the key of C major is created with the following chords: Dm, G, C.

Let’s do another one in the key of G — Am, D, G. Easy, right? 

So … what’s the big deal?

You may be saying, “I’ve played all these chords before. Who cares?” Well, this specific chord progression occurs extremely frequently, and within this specific cadence lies a hidden world of harmony for us to explore. Let’s get started. 

Scales, Arpeggios, and more scales

If the three chords in question are all derived from the same scale, you could run up and down that parent scale for a solo or create a melody, and that would certainly work — this is sometimes called “playing above the changes.” However, there is a different, more interesting approach — it’s called playing “inside the changes.” 

The idea is to use the notes in the scale deliberately and with intention; instead of just playing the C major scale up and down, use the notes of any given chord at that moment (arpeggios). 

Once you’ve mastered the parent scale and arpeggios, you can begin experimenting with scales other than the C major scale and its modes. For example, try playing the G whole tone scale or the G half-whole diminished over the V chord. An endless array of new sounds is possible, so open your ears and dig in!