The Andalusian Cadence and the Phrygian Dominant Scale

The Andalusian cadence is a well-worn non-diatonic chord progression that's easy to improvise over if you use the approach presented here...

I was inspired by an old Eric Haugen YouTube video to experiment with the Andalusian cadence, and I was thrilled by how well the rectangle and stack approach and pentatonic gear shifts work, even when you mix in the harmonic minor scale (in this case, more appropriately called the Phrygian dominant scale).

I plan to do a video lesson on this topic soon, but for now, here are the core insights laid out on paper. There's an 8-page PDF lesson and an all-new backing track.

Check it out!

The Andalusian Cadence and the Phrygian Dominant scale

Introducing the Andalusian cadence

The Andalusian Cadence is a common chord progression used in a variety of music, from traditional Jewish music (“Hava Nagila”), to surf rock (“Walk Don’t Run” by the Ventures), to folk rock (“One More Cup of Coffee” by Bob Dylan). It’s a four-chord progression, usually played in a loop, and a typical version of it is:

Am G F E

If you try to improvise over this progression, you’ll quickly find that you can’t find a single scale that fits over all four chords. This is easy to see when we plot the notes from each note on a single string. Here, all of the chords are referenced relative to the chromatic scale starting on A:

Indeed, there are eight notes in play if we plot them all together.

It turns out that the E major chord is the troublesome one. If we eliminate it, the first three chords contain all of the notes of the A Aeolian mode:

This is equivalent to the C major scale, but since we hear A as being home, it’s more correct to think of this as the A natural minor scale, or Aeolian mode. The E major chord almost fits, but it contains a natural 7 of A rather than a flat 7.

So, what’s really going on here?

It turns out that it is common in minor keys to substitute a major chord for the V chord, which creates a strong pull toward the i chord. This is because the major third of the V chord is the leading tone (the natural 7th) of the i chord. That’s exactly what’s happening in this chord progression.

We’ll need to be careful about our notation here, and I’m going to use both the classical and Nashville number systems to make this clear.

The classical number system treats the home chord as the “one” chord, and it uses Roman numerals to indicate the chord function, with lowercase to indicate minor chords. So in classical notation, this chord progression is:

i bVII bVI V

That’s because if the key is A, the Am chord is the i chord. G is a minor seventh interval above A, so G major becomes bVII (a major triad built on the ♭7). F is a minor sixth above A, so F major is bVI. E is a perfect fifth above A, so E major is represented as V.

Nashville notation references everything to the parent major scale, so if we’re treating this chord progression as being in A Aeolian, we’ll reference everything to C major (the relative major key). Nashville notation traditionally uses Arabic numerals, with a minus sign (‘-‘) to indicate minor.¹ So in

Nashville notation, this chord progression is:

6- 5 4 3

That’s because A is a major sixth above C, so A minor is represented as 6-. G is a perfect fifth above C, thus becoming 5. F is a perfect fourth above C, so 4. And finally, E is a major third above C, so 3.

Okay, so who cares? Is this just music theory for music theory’s sake?

It’s worth recognizing and understanding both forms of notation and the common practice of changing the V chord in a minor chord progression into a major triad or dominant 7 chord. This substitution happens a lot, and there’s a well-worn solution for how to improvise over these chord progressions.

Over the first three chords of this chord progression, we can use the A Aeolian mode, or we can use the one-pentatonic-scale-per-chord approach and play A minor pentatonic over Am, G major pentatonic over G, and F major pentatonic over F. In a sense, both approaches are using the A Aeolian mode, since all three pentatonic scales are embedded inside the Aeolian scale.

If you translate the chord progression into Nashville notation, you can use the scale-shifting approach from the Pentatonic Gear Shift series to do this easily. I’ll show you exactly how to do this later in the lesson, but first, we need to take a detour.

The only place the one-pentatonic-scale-per-chord approach doesn’t work well is when we get to the E chord. The problem is that the notes of E major pentatonic clash too much with the notes of A Aeolian:

The E major pentatonic scale has three notes that aren’t in A Aeolian, and that’s too abrupt of a shift for our ears.

Introducing the Phrygian dominant scale

When a minor chord progression contains a dominant V chord, classical music theory tells us that we should use the harmonic minor scale.

In this chord progression, the Am, F, and E chords fit the scale perfectly. The root of the G chord is the only note that doesn’t fit.

One of the most pleasing ways to solo over this chord progression is to use A Aeolian (or the one-pentatonic-scale-per-chord approach) for the A, G, and F chords, and then switch to A harmonic minor for the E chord.

Note that we could use A harmonic minor over the A, F, and E chords and switch to G major pentatonic for the G chord, but that doesn’t sound quite as good. I don’t know why. Possibly it’s because our ears are just accustomed to hearing it the other way.

Okay, but if we’re only going to use the A harmonic minor scale over the E chord, it makes sense to think of the notes of that scale in terms of E. The Phrygian dominant² scale is another name for the 5th mode of the harmonic minor scale. So if we start from the A harmonic minor scale but treat E as the root, we’re playing E Phrygian dominant.

How to visualize Phrygian dominant

The minor and major pentatonic scales don’t fit the Phrygian dominant scale well, but if we raise the flat third of the minor pentatonic scale to create a dominant pentatonic³ scale, we get a better fit.

We can visualize this on the fretboard by modifying the minor pentatonic rectangle and stack shapes like this:

And we can extend these shapes to cover the full Phrygian dominant scale by adding in two more notes in the “dark” hidden in plain sight⁴ positions:

As an aside for the true nerds, you can also use the “staggered” hidden in plain sight positions to play the 5th mode of the melodic minor scale, aka Mixolydian ♭6, aka the Hindu scale:

Putting this into practice

It’s fairly easy to play all four chord scales in one position on the fretboard if you use the Pentatonic Gear Shifts methodology. Recall that when using the gear shifts, the 6- and 1 pentatonic chord scales are in the neutral position. The 2- and 4 pentatonic chord scales are found by shifting up one string set, and the 3- and 5 pentatonic chord scales are found by shifting down a string set. As shown in the horizontal shifts lesson, we can also move from 2-/4 to 3-/5 by shifting up two frets, and we can move from 3-/5 to 2-/4 by shifting down two frets.

My favorite place to solo over the Andalusian cadence in Am is to start in Form 4 of the Am pentatonic scale at the 12th fret:

Then we can shift down a string set to play the G major pentatonic scale:

From there, we can shift up two strings (up one from the neutral position) to play the F major pentatonic scale:

And then, over the E major triad, we can play the E dominant pentatonic scale. E major is the 3 (major) chord in Nashville notation, so we can play this in the down-shifted position, substituting the dominant pentatonic rectangle and stack for the normal minor pentatonic shapes:

Or, we can take it further and use the hidden in plain sight method to play the full mode for each chord. We’d use the staggered position to play the A Aeolian mode:

We’d use the dark position with the G major pentatonic to play the G Mixolydian mode (since G is the 5 chord in C major):

We’d use the bright position with the F major pentatonic to play the F Lydian mode (since F is the 4 chord in C major):

Notice that the three scales we just played all contained the exact same set of notes, but by visualizing them with this framework, we would emphasize different notes while playing.

Finally, here is the full E Phrygian dominant scale created by filling in the dark positions of the Dominant pentatonic scale:

As another example, we could start in Form 1 of the A minor pentatonic scale at the fifth fret:

To play the G major pentatonic scale, we would shift down one string set:

To play the F major pentatonic scale, we can either shift up two string sets:

Or we could shift down two frets:

Our choice of E dominant pentatonic scale location depends on where we played the F major pentatonic. If we had stayed at the 5th fret, we’d shift back down two string sets and play the modified shapes:

If we had shifted down to the third fret, we’d have to shift up two string sets to play the dominant pentatonic shapes:

As you can see, the dominant pentatonic shapes are less natural to play than the pentatonic rectangles and stacks (I like the 12th position version of this best because I find it the easiest to play), but if you know the pentatonic rectangle and stack approach really well, it’s not that hard to adapt it like this, starting from any of the five standard pentatonic positions.

This lesson includes a backing track of the Andalusian cadence in A minor, and I encourage you to try out these approaches and see for yourself how well they work.