Pentatonic Substitution

Andy | October 21, 2014 | 9 Comments

The minor pentatonic scale is probably the most well known scale to modern guitar players, it’s simple shape is easy to remember and comfortable to navigate across the guitar. For that reason, it is incredibly useful, especially during improvisation. However, we only really scrape the surface on the usefulness of this scale, and this article provide another use for us to explore.

Pentatonic substitution is the process of superimposing the minor pentatonic scale over an alternative degree of an underlying chord in a given progression. The effect of this is that we highlight certain intervals against a chord, giving character to our note selection.

The following examples will be based on C chords, so for reference, the notes and intervals of C Major are below:

C Major Notes & Intervals

C Major Notes & Intervals

Let’s start off by looking at a Cmaj7 chord:

C Major 7 Chord

C Major 7 Chord

The intervals of a Cmaj7 chord are: I – III – V – VII

If we play a minor pentatonic scale off the third degree (E), we get the following intervals:

III – V – VII – IX – XIII

You may notice, that the root note C, is omitted from our note selection. This in itself will remove the predictability of the melody being produced, as the resolving nature of the tonic note is not played. However, we have still included all the remaining chord tones, as well as introducing the 9th and 13th extensions, giving this option a rich yet inside feeling.

Let’s next look at a C7 Chord:

C7 Chord

C7 Chord

The intervals of a C7 chord are: I – III – V – VIIb

If we play a minor pentatonic scale off the fifth degree (G), we get the following intervals:

I – V – VIIb – IX – XI

Using this option, we remove the third interval, however retain the root, fifth, and characteristic dominant seventh interval. We also add the ninth and eleventh extensions, adding a bit of spice and tension to the harmony created.

Now let’s look at a Cmin7 chord:

Cmin7 Chord

Cmin7 Chord

The intervals of a Cmin7 chord are: I – IIIb – V – VIIb

If we play a minor pentatonic scale off the fourth degree (F), we get the following intervals:

I – IIIb – VIIb – XI – XIIIb

This option, whilst omitting the fifth interval, really highlights the minor tonality of the chord.

The eleventh extension gives texture, whilst the flattened thirteenth adds a true aeolian feel. It’s worth noting that this is only one note different from the obvious option of playing a standard C minor pentatonic scale, in that we have traded the fifth interval for the flattened thirteenth, adding a touch more tension to the sound.

Finally, let’s look at a Cmin7b5 chord:

Cmin7b5 Chord

Cmin7b5 Chord

The intervals of a Cmin7b5 chord are: I – IIIb – Vb – VIIb

If we play a minor pentatonic scale off the minor third degree (Eb), we get the following intervals:

IIIb – Vb – VIIb – IXb – XIIIb

This option, omits the root note, however it does not feel missed. Having every interval flattened, gives a strong diminished effect to this scale choice, and highlights the dark sounding nature of the min7b5 chord.

There are of course other options to those suggested above, and certain choices will work better in certain situations. This is a great concept to get into, and an ideal entry into the practice of superimposition. It is a very useful tool for writing interesting harmonies, and improvising over quick chord changes and complex modulations.

Explore the concept further by experimenting with other options, superimposing the minor pentatonic scale off alternate intervals. See what extensions are created, and compare with any modal knowledge you may previously have studied.

Article by Adi Hughes. See more from Adi here: www.adihughes.co.uk

Category: Guitar Theory

Comments (9)

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  1. Alan Jackman says:

    Eh. I’ve been playing guitar for over 7 years and I’m pretty confident with minor/major scales, but honestly – I didn’t understand much from this article. My music theory level is not good enough to grasp the points of this post. Maybe I try again in the future and it will make sense to me then;)

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  3. donnie E says:

    Stan – as to why a certain degree is chosen, it’s simply a matter of corresponding tones. The whole idea here is to use the minor pentatonic scale. The Em pentatonic (E-G-A-B-D) contains three notes of the Cmaj7 chord, and includes two other tones A, and D that are the same tones as the 13th and 9th of Cmaj7. You MAY Certainly use other degrees, you can put an A minor pentatonic over the 6th degree of C, and you end up having A-C-D-E-G, which are tones 6, 1, 9, 3 and 5 of the C. The end result is you have very consonant chord tones combined with a step into color tones, and since most players are very familiar with the pentatonic scale, you can “play” around with the scale and really not do any damage. Interesting that both these example introduce the 9th and 13th into the sound.

  4. Donnie M. says:

    Starting to feel like calculus, not fun.

  5. Andy says:

    Basically, instead of just playing a C scale (mode) over a c chord, you can take any pattern through the c scale, ie: Playing in Key of C,: you have C maj, D min, E min, F maj, G/7, Am, Bm7-5 (or half diminished), now, this does not mean you would play any of these scales entirely, instead, while ‘jamming’ over your C progression, play through the notes in these ‘patterns, modes, scales,’ and find the notes in each pattern that create ‘your unique sound’. This theory is really about freeing up your mind & fingers, and finding ‘notes with color’, it might sound strange at first. Once you ‘hear the difference’, you will have a ‘new smile from ear to ear’, and …… your friends and jamming buddies will really love your new sounds. Most important of all, play for the enjoyment, take your time, and learn to listen. I am so glad a friend taught me these principles late last year, it took me a couple of months to figure out what he meant, now he smiles and says “that’s what I’m talking about”, All the best to all of you with your playing.

  6. Max says:

    Good question. I can explain most of it. In the key of C, the third degree, E min is often used as a sub for C maj. Therefore, an E min pentatonic scale will work. And A min and D min are options also but will give a different “flavor”. This the ii, iii and vi are viable options in a major key.

    Regarding the C min, which is the ii chord in Bb. F is dom V chord. In jazz applications, there is some interchangeability with this relationship. Thus the F min pent will work fine. Try also working with minor penatonic scales for the ii, iii and vi in the key of Bb : whic is C min, D min and G min.

    C7 is the V chord in the key of F. G is the minor two in F (again a ii / V). The ii, iii and vi in F are worth exploring.

    The Cm7b5 is the vii in the key of Db. Thus the Eb is the ii chord and the minor penatonic scale can be applied. Hope this helps..

  7. Iain says:

    Please translate to English

  8. James says:

    seems like there’s always someone that want’s to contradict or correct even though they’d be nowhere close to understanding the concept without the advice you just gave …

  9. Stan says:

    Hi, Interesting approach, however, I now have more queries. How and Why do you chose the various degrees over the chosen chords? Like over the CMaj7 you say 3rd degree, can we use others. Then the interval usage seems random. Other than just take what you’ve said and memorize and use verbatim. I can’t see using this concept without understanding the how and why.

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