Throughout, I apply the disclaimer that I am only teaching what I know from my years as a music student and a guitar player. I may have different ways of explaining concepts or different terms for common concepts than others, but music is not a highly standardized field outside of the realm of classical and perhaps jazz. If I print a genuine error, please feel free to bring it to my attention.
"But I've got my philosophy..."
To start, I think pentatonics are among the most misunderstood and underrated areas of theory and technique among modern guitarists. It's easy to look down on a player for "just ripping out a bunch of pentatonic riffs," or to dismiss the concept as too "simple" since it cuts out considerable opportunity for color shading with missing tones from the diatonic sound. I believe, however, that no single tool in the aspiring soloist's toolbox is more important than mastering the many facets of pentatonic scales and figuring out how to correctly apply them.
Pentatonics ab initio
Customarily, music is defined by a 12-tone scale spanning each octave... A B C D E F G, with a whole pile of little #'s and b's tossed in to mark the half steps between the wholes. However, music that randomly uses all of the possible tones all over the place sounds a bit disjointed and has no clear color.
As a result, we tend to limit our vocabulary so that we may speak more clearly; the foundation of Western music is the major scale, a diatonic scale, which means it is comprised of only 7 tones. One drawback of a diatonic scale, however, is that there are still plenty of opportunities to play "wrong notes," e.g. a note that does not follow the modal tone implied by a chord progression. The song might be in C major, but the C major scale might not always sound right or might have shaky spots.
Enter the pentatonic scale, a further restriction of our note vocabulary. A pentatonic scale, by definition, only has five tones. The goal of the scale is basically to eliminate strong "color" notes which have the highest potential for creating discord. It is the most "vanilla" of the scales mentioned thus far, but it also reduces risk to an improviser and carries a distinctive, familiar sound.
The minor pentatonic scale
This is METALGUITARIST.ORG, so let's not fuck about, shall we? While the foundation of Western music is the diatonic major scale, rock and metal's favorite sounds come from the various minor-sounding modes pulled from it. They're just more badass.
In terms of interval values, the most common minor-sounding mode, Aeolian ("natural") minor, is constructed as:
From it, the pentatonic minor is constructed as:
Note that all we've done is remove the 2nd and flatted 6th degrees from the Aeolian mode.
Well, what if instead of Aeolian, the underlying chord progression instead implies a Dorian sound with a major 6th interval? Go ahead and shred some flatted 6ths over such a progression, and you'll sound like shit. Some might call it "jazzy," but unless you sell it pretty well, it's just going to be shit. Since the pentatonic minor has eliminated 6th scale degrees entirely, it can freely be used over either progression and will still sound fine.
The same applies for a Phrygian-sounding progression. That pesky flatted 2nd degree will clash if one tries to play the natural minor scale over it, but with the pentatonic minor, you're still golden.
This is all very well and good, but get on with it!
Alright then, I'm putting you to work. If you want to master the pentatonic scale, you need to spend a lot of time with it so that it falls under your fingers effortlessly.
"But Soop, that's like all I do, man! Pentatonics FTW!"
"Ah yes, but did you know you could play them outside of the general 12th fret region?"
It's true! The fact that everybody picks up and gets entirely too cozy in the E minor pentatonic scale box is one of the principle reasons that more experienced players like to shit on this scale.
The box (vertical pattern of intervals) with which everyone is most familiar is called Box 1, where the lowest point of the box holds the root/tonic/"1" of the scale. All examples in this section are in A pentatonic minor, both because it has no sharps or flats and because it gets us away from familiar territory.
Root notes (A's) are marked with an *.
Box 1, A minor pentatonic
- Play this shape approximately 1000x, or more if you're not bored yet.
- Use only your 1st and 3rd fingers (develop that 3-fret stretch slowly if it feels uncomfortable). I also recommend strict alternate picking.
- Try not to think of the exercise in terms of fret numbers or note names, but as a pattern of intervals. This will make it easier to shift to other keys later. Keep reminding yourself which box you're in.
- Play as slowly as you need to, with a metronome, such that you play cleanly and without missing any notes after you've got the pattern memorized.
- When you do get bored, try double-, triple-, or quadruple-picking the pattern (i.e. 5555-8888-5555-8888-5555-7777...)
- Put your guitar in your lap the next time you're watching an episode of the Simpsons or something else you're familiar with. Zone out, don't watch the fretboard, and just slowly and carefully run the scale up and down, burning the pattern in.
- Challenge yourself to name the scale intervals aloud as you go: "1, flat 3, 4, 5, flat 7, 1..." When you're doing this, make it a point to stop at the 1's and get a feel for where the tonic notes are. They're important for resolving lines.
Once you've worked that a whole bunch (seriously, work on it for a day or two at least!) continue in a methodical fashion on to the rest of the boxes in this key.
And just for good measure, here's Box 1 again, but at the higher octave. We're going to eventually build a loop that lets us connect everything across the whole board, so it makes sense to be able to play every available box.
Box 1 (higher octave)
Can you play Box 5 below the lower-octave Box 1? Give it a whirl.
That's all for now
I understand that there isn't anything terribly "musical" in these examples, but have some faith that we're going somewhere with this. Even if you're pretty good at ripping out some Zakk Wylde licks, most people aren't familiar with all the boxes and how they relate sequentially, and it never hurts to study things you think you're already familiar with.
With that, I'm going to grab my metronome and work a couple of these myself.
Thanks for keeping me around!