Sunday, August 30, 2009

Dominant Pentatonic Scale

Q: I read a column about the dominant pentatonic and I'm feeling a little confused. Here's why... The dominant pentatonic comes from the Mixolydian Scale, and I know this mode and have no problems with that. Now the pentatonic takes only five notes of this scale. My problem here is what are these five notes? The Mixolydian looks like this: 1-2-3-4-5-6-b7 What should be the formula for the dominant pentatonic? Should it be this: 1-3-4-5-b7 (referenced here >>>): 

Or should be this one:
1-2-3-5-b7 (referenced here >>>):

Because in fact both use only five notes, and in both, the five notes come from the Mixolydian Scale, so which one to use? I've seen in several places the first one, and in others the second one. Thanks a lot for any info!

I can see how this might confuse you. Let me see if I can shed some light on the subject. First of all, you'll be happy to know that there is no set standard pentatonic scale called the dominant pentatonic scale, so there might be several different examples floating around out there. As you probably know the most common pentatonic scale used for dominant chords would be the minor pentatonic: 1-b3-4-5-b7.

The examples you picked up are synthetic pentatonic scales, for the lack of a better name. Now this does not mean that they are wrong or anything and are fine to use in the right circumstances. Pentatonic simply means five notes so there are plenty of combinations you could make from any 7-note scale. Now the first one you describe is a common synthetic pentatonic scale that was probably made popular by Jan Hammer (matter of fact, I have heard it referred to as the "Jan Hammer Scale" before.

Here is the trick with this scale and how you can do the trick to make different pentatonic scales. Before I do this, let's make sure you know exactly what the "standard" two western pentatonic scales are. They basically eliminate the half steps from both the major and minor scales:

Major Pentatonic: 1-2-3-5-6

Minor Pentatonic: 1-b3-4-5-b7

These "standard" pentatonic scales work well with the 7-note modal scales because the same pentatonic scales work as good replacements for most of the modal scales. In other words the major pentatonic (
1-2-3-5-6) can be found in the three major modes (ionian, lydian and mixolydian) and the minor pentatonic (1-b3-4-5-b7) can also be found in the minor family modes (aolian, dorian and phrygian):

Ionian: 1-2-3-4-5-6-7
Major Pentatonic: 1-2-3-5-6

Lydian: 1-2-3-#4-5-6-7

Major Pentatonic: 1-2-3-5-6

Mixolydian: 1-2-3-4-5-6-b7

Major Pentatonic: 1-2-3-5-6

Nothing changes here right? How about the minor modes:

Aolian: 1-2-b3-4-5-b6-b7

Minor Pentatonic: 1-b3-4-5-b7

Dorian: 1-2-b3-4-5-6-b7
Minor Pentatonic: 1-b3-4-5-b7

Phrygian: 1-b2-b3-4-5-b6-b7
Minor Pentatonic: 1-b3-4-5-b7

Now let me explain what we will call, modal pentatonic scales. Again this is my description and just like there is no standard term like "Dominant Pentatonic" there also is no standard term "modal pentatonic." But let's just use the term for the lack of a better one. What we are going to do is use the formula for the minor pentatonic (
1-3-4-5-7) and use it for the major family modes adjusting the intervals accordingly. After that, we will take the major pentatonic formula (1-2-3-5-6) and apply it to the minor modes.

First let's take the minor pentatonic (1-3-4-5-7) formula and apply it to the major family modes starting with mixolydian. We will have to lower the 7th because the mixolydian scale has a minor 7th:

Mixolydian: 1-2-3-4-5-6-b7
Mixolydian modal pentatonic: 1-3-4-5-b7 (based on the formula for the minor pentatonic scale) This is the scale that was referred to as the "dominant pentatonic scale," we made it by applying the minor formula to the mixolydian scale.

Lydian: 1-2-3-#4-5-6-7
Lydian modal pentatonic: 1-3-#4-5-7

We can take the major pentatonic formula (1-2-3-5-6) and apply it to the minor modes as well:

Dorian: 1-2-b3-4-5-6-b7
Dorian modal pentatonic: 1-2-b3-5-6

Phrygian: 1-b2-b3-4-5-b6-b7
Phrygian modal pentatonic: 1-b2-b3-5-b6

Aolian: 1-2-b3-4-5-b6-b7
Aolian modal pentatonic: 1-2-b3-5-b6

Locrian: 1-b2-b3-4-b5-b6-b7
Locrian modal pentatonic: 1-b2-b3-b5-b6

So there is how your first dominant pentatonic scale comes about.
Your next example is also just synthetic and the person who made it simply eliminated the 6th from the major pentatonic scale and replaced it with the b7th from mixolydian.

Mixolydian: 1-2-3-4-5-6-b7

major pentatonic: 1-2-3-5-6

synthetic: 1-2-3-5-b7

Another great pentatonic scale for the Blues can be made by replacing the b7 in the minor pentatonic scale with the major 6th. That scale looks like this: 1-b3-4-5-6. I love this sound and use it all the time in the Blues. The major 6th in the scale gives you a super major sound over the I chord and the same 6th in the scale becomes the major 3rd over the IV chord.

There are actually countless pentatonic scales used all over the world, for example this one used by the Japanese in Okinawa: 1-3-4-5-7

To make this even more confusing, you can also superimpose various pentatonic scales over individual chords for outstanding results. Just for example:
Lydian = minor pentatonic on the 3rd, 6th and 7th (E lydian = G#, C# and D# minor pentatonic scale).

But as far as I know, there is no one standard dominant pentatonic scale. So as far as which one to use, whichever you like is fine.


Sunday, August 9, 2009

Modes and Slash Chords

How are you? I was just going over some of your lessons online and found them very interesting. I do have a question:

I am currently using the C Mixolydian mode to jam/solo over the root of the mode (C). I am very confused on what chords to use. I saw a video of Frank Gambale explaining this but I can't understand this. He mentions to use the 4th and 5th chord of the major scale. To me, the major scale of C mixolydian is F major...correct??? do I play a B and C? If I am wrong, what am I doing wrong??? I would appreciate any help

Glad you like the lessons. You have to understand the diatonic system to use the modes properly. As you described, you always use the mode over the diatonic chord of the same name right? So C mixolydian works over a C7 chord. Here is the diatonic system for C mixolydian, the key is F major:

I - F (or Fmaj7) - Ionian
ii - Gmin (or Gmin7) - Dorian
iii - Amin (or Amin7) - Phrygian
IV - Bb (or Bbmaj7) - Lydian

V - C (or C7) - Mixolydian

vi - Dmin (or Dmin7) - Aolian

viio - Edim (or Emin7b5) - Locrian

Now probably what Frank is saying, is that the IV and V chords of this key, played over the root of the mode are good slash chords to play for a modal vamp. The IV and V chord in the key of F are Bb and C right? So play these over the C root, as in: Bb/C - C/C (C/C is really just a C triad). So this is a good progression to jam on. This will work for any of the modes:

Bb lydian for example: Bb and C over the lydian root: Bb/Bb - C/Bb (really Bb - C/Bb). This is good for Bb lydian.

D aolian: Bb/D - C/D

A phrygian: Bb/A - C/A

All these examples are simply the IV and V chord played over the modal root. Of course this is just a simple way to practice and you can simply make up progressions from the modal chord. Just don't mix up the chords too much or you will lose the modal sound. Two chords are usually best. C mixolydian: C7 - Dmin7 or C7 - Bbmaj7 for example.