The Minor Pentatonic can be considered essential for all blues, folk, rock and many other styles of music. If you have not learned it already, you should definitely take a minute or two now and do so.
The Minor Pentatonic scale (henceforth referred to as “MP”) is a 5-tone scale (penta=five + tonic=tone), consisting of root, b3, 4, 5 and b7. The main intervallic omissions of the MP (compared to most other scales) are any kind of 2 or 6. Since the state of the 2 and 6 (natural or flatted) often differentiate the many available minor scales from one another, the MP thus avoids a good deal of potential sonic conflict, and so is very good at covering a multitude of harmonic contexts. In other words—unless you’re playing extremely vertical chord progressions (e.g. jazz), it’s usually VERY hard to hit a wrong note in a minor key using this scale. Hence its eternal popularity ever since minor tonalities evolved, centuries before blues blossomed from the sweltering bowels of Dixie. The MP can cover all manner of minor key jams (Oriental and Celtic included), as well as dominant-chord-based blues progressions.
“The Box”
Here is the first Minor Pentatonic scale every guitarist inevitably learns:
The red notes are root tones. So you can see that this fingering covers 2+ octaves. It will fit perfectly over a standard minor barre chord rooted on the 6th string:
and oddly enough, works just as perfectly over a dominant barre chord:
(Why the minor third of the MP works over a dominant chord, which contains a major third, is one of the great mysteries of music. One of these days I’ll have to consider the matter more deeply and come up with a theory.)
The Blues Scale
We see many sources refer to the MP as “the blues scale”. This is incorrect. Admittedly, you’ve got most of a blues scale with a MP, but not the vital component that makes the blues cry as it does. We need to add just one note to the MP scale to make this happen. The Blues Scale consists of root, b3, 4, b5, 5 and b7. In other words, add a b5 to a MP and you have the true, righteous and everlasting Blues Scale:
It is obvious to any but the most tone-deaf ear that adding the b5 to the minor pentatonic takes this scale out of the universal into the realm of good old American kick-ass. By simply adding the b5, we leave the world of abstract ephemeral space noodling and enter the world of blues, of rock, of pain and suffering and redemption. It is nothing new that the b5 (aka tritone) should have such a profound affect on a listener’s experience. In pre-modern times, use of a flatted fifth (often called the “devil’s interval”) was to be avoided at all costs. You may as well have spit on the Pope as try to sneak a blue tone into your jams back in those days! Thankfully, auditory perceptions have loosened up a bit since then.
Application
Let’s play a blues in the key of G, shall we? You need to position the MP and/or Blues scale(s) in the key of G (low note in the scale is at the 6th string, 3rd fret). Play over this standard 12-bar blues progression:
Blues in G
MP3 Jam Track (four times through the progression)
Copyright 2002 Jeff Foster. All Rights Reserved.