In this article we'll take a look at some advanced pentatonics concepts, first examining how pentatonic scales are derived and then looking at a very common left hand comping device that uses the minor pentatonic scale. This left hand comping structure is an advanced jazz sound that uses the tones of the minor pentatonic scale to create quartal voicings (more on that below).
What Are Pentatonics?
Let's first understand what the word pentatonic means. The word penta means "five" and tonic means "tone." So the word "pentatonic" literally means "five tones." And that's exactly what a pentatonic scale is - a five tone scale. But which five tones?
Major and Minor Pentatonic Scales
Just as every major scale has a relative minor scale that shares the same tones (because they share the same key signature), every major pentatonic scale has an equivalent minor pentatonic scale which uses the same tones.
The major pentatonic scale uses five notes from the major scale - the 1st, 2nd, 3rd, 5th, and 6th scale degrees. So, if we take an Eb major scale and extract only these 5 scale degrees, we will get an Eb major pentatonic scale.
Now consider the relative minor of Eb major - the minor key which shares the same key signature as Eb major. The answer of course is C minor. Eb major and C minor are relatives because they share the same key signature, and therefore the same notes in their respective scales. But in order to create a minor pentatonic scale, we use only the 1st, 3rd, 4th, 5th, and 7th scale degrees. Taking these tones from a C minor scale gives us the notes C, Eb, F, G, and Bb. Notice any similarities? They're the same notes as those used in the Eb major pentatonic scale. So the Eb major pentatonic scale and the C minor pentatonic scale use the same tones.
Left Hand Comping Ideas
The left hand comping idea we're going to look at is referred to as a quartal voicing (quartal, meaning "4ths") and can be constructed using notes from the minor pentatonic scale. Let's first take a root position C minor 7 chord:
Using only the notes from a C minor pentatonic scale we can create two quartal structures for Cm7. By starting on the 'F' and stacking 4ths ('Bb' and 'Eb') and then moving that structure up a whole step and stacking 4ths starting on 'G' ('C' and 'F').
To really bring this sound to the advanced pentatonics jazz level, practice playing the root and 5th of the chord (C and G) and then playing the quartal voicings, all with your left hand:
The jazz pianist McCoy Tyner, among others, popularized some of these left hand quartal comping voicings. Check out his tune "Passion Dance" to hear it used extensively, as well as on tunes such as "Impressions" and "So What."