In a previous blog post, I talked about how you can breath new life into pentatonic scales by playing them across three note per string shapes. But we didn’t much talk about how useful to build them and identify them.
Although 5 (quick aside, penta means ‘5’) note scales have been around for a good while, they still bear significant presence on today’s modern music across the world. There are a few different types of pentatonic, which can be categorised as hemitonic and anhemitonic scales. In this post, we’re focusing on the two more commonly used pentatonic scales, major and minor. Both are anhemitonic, meaning they don’t contain any semitones. If you’re interested, the Wikipedia article on pentatonic scales cites a few different variations of the pentatonic, including the Japanese and Egyptian scales.
Pentatonic Scales Theory – Major
The major pentatonic scale is built up of the following 5 intervals. Note the the distance between the 3rd and 5th degrees are a tone and a half.
1 (T) 2 (T) 3 (T+ST) 5 (T) 6
From here, we can see that the pentatonic scale misses the 4th and 7th degrees of the scale. In some ways it can be perceived as an incomplete scale. But the pentatonic scale conveys it’s own feel and is still complete in it’s tonality. Taking away these degrees of the scale, is how the pentatonic scale is so versatile. You can play it over modes or 12 bar blues progressions with ease.
Pentatonic Scales Theory – Minor
For the minor pentatonic scale, much like triads for example, we need to flatten certain notes available to us. In a seventh chord for example, you’d flatten the 7th and 3rd degrees. Well… guess what….
1 (T+ST) b3 (T) 4 (T) 5 (T+ST) b7
Notice how the this pentatonic makes use of the 4th, and the flattened 7th degrees but takes out the 2nd and the 6th. As the interval of a tone plus a semitone is also interpreted as a minor 3rd, the degrees of the scale that we get in this pentatonic are different to your major.
Why does the pentatonic work so well?
It’s a universally beloved scale shape and sound, but it’s not always as simple as “it’s got less notes than a normal scale!” The absence of the 4th and 7th degrees in this pentatonic, is what helps the scale sound so pleasing. These degrees are considered slightly dissonant compared to the others. In a the seven note scale, the distance between these two notes is a tritone. An interval that conveys suspense and a lack of resolution. Without them, as shown in our pentatonic scale, we’re lacking this tension so that scale works so nicely around a plethora of progressions.
Let’s take a look at the CAGED pentatonic shapes. These are movable so experiment with playing these from any starting root note on the neck. Learning these patterns will help unlock the potential that the pentatonic has on the guitar.
Take some time to learn these as just shapes to begin with. Practicing them over known chord progressions to help you get in tune with how the pentatonic scale sounds. If you’re interested, a good tool to help further in recognising the pentatonic out of the full scale, is this one from teoria.com. You can use this tool for both major and minor scales. Speaking of which, let’s look at the shapes for the latter.
Notice that there are no new shapes when learning the this pentatonic. It’s all relative to where the root lands. The E shape in minor, is the same as the G shape in major, it’s just the root position and intervals that change.
A great way to practice your pentatonic scales in a practical context, is along to a backing track or by jamming along with other musicians. Study the shapes individually, and see if you can apply them to a given chord progression. A very common progression is the I IV V (or i iv v). Meaning, the first, fourth and fifth chords in the diatonic chords in your given key. More on diatonic chords here!
For a really insightful view in to the immense practicality of the pentatonic, check out this video with Bobby McFerrin.
Don’t forget, you could claim a free lesson with yours truly to help further apply this knowledge. As well as gain direction on where to go next with your playing in general. Click here to get in touch!