Pentatonic guitar scales are possibly the most popular & most used melodic maps on our planet. One way we learn them is using frames (grids, maps, charts). The following map of these scales is often the first complete scale system a student learns. It is a 'hollowed out' Major/minor scale system [it is 'missing' the 4 & 7 to the Major, & those same tones are the 2 & 6 to the minor].
The pentatonic scale is any scale with 5 tones, yet in Western music, it specifically refers to the Major & minor types. Each of these have a specific formula, or set of tonal relationships that create the sound of Major & minor pentatonic.
The Major pentatonic scale formula is R 2 3 5 6. This scale is the main riff in 'My Girl' performed by the Temptations.
The minor pentatonic scale formula is R b3 4 5 b7. The same 5 tones, just calling a different tone the root.
The basic rule for scales is that the number of tones in it (not any doubled tones - just the different ones), is the minimum number of names that the scale can have (each tone of a scale can be a starting point).
Since there are 5 tones in pentatonic guitar scales, & each tone can be a root of a scale (modal perspective on pentatonics), the scale has 5 names (the Major & minor pentatonic, plus the 3 below).
Take special note of the octave shapes. They say quite a bit - We can see the chord forms outlined with octaves. In a way, both chords & scales wrap around or fill in octaves. Memorize the octave shapes.
R stands for Root. A Root is the base tone for something (chord, scale, arpeggio) to be built. It is the tone that names the chord, scale, or arpeggio. In this case, it is the root of a system of pentatonic guitar scales (Major/minor).
When we use a flat like this, it means we are comparing or paralleling to what is normal to the root. What is normal means what is derived from the Major scale for the root.
For A minor, the C is a flatted 3, because in the key of A Major (the A Major scale), the 3 is C#. Likewise, since the 7 in A Major is G#, G is the flatted 7 (b7) to A.
When learning a guitar scales system like this, it is important to view it from multiple perspectives.
One way to think about this is that each adjacent frame shares a border. Since there are 2 tones per string in each pattern, we can think of all of the lower of the 2 (across all strings), as a block - the head. And, the higher tones (across all strings), as the tail. The tail of one pattern, when moving up, becomes the head of the next.
Another way is that we can learn every other pattern and thus know the ones in between: learn frames 1, 3, & 5, and we automatically know 2 & 4.
One way is to learn these really well is to stitch the patterns together. Choose 2 frames. Use 2 strings (adjacent string couplet) from those 2 frames (i.e. the 1 & 2 string). This totals 6 tones. Improvise on these 6 tones. Explore double-stops in every combination. Then go to next two frames and do the same thing (i.e. 2 & 3). Move through all 5 frames using 2 string couplets [sets of 6 tones]. Then do same with the other string couplets.
By doing this, we are connecting the frames & learning how to move between them (sliding is a great way to transition to next). The middle two tones are both a head & a tail [head - head/tail - tail].
As with all pattern learning, learn them, yet keep in mind that when we solo or improvise, we think in melodic ideas, not patterns. And, to really know and use these, it is important to know tonal names & relationships. Using patterns is a simple way to get going, but we are always looking to transcend the maps. Our big goal is learning to be melodic. Another consideration is that you may just use pieces of the system for a given moment in time, rather than running the whole board [the chords we are soloing against may not last long].
In real time, patterns can fail us. There are higher levels of knowing & understanding. We learn the maps to forget them. Reference playing [using maps] should ultimately lead to non-reference playing.
Let's end with an important & pertinent cliche: "The map is not the territory." - Alford Korzybski. Alford would want us to get to know these pentatonic guitar scales in terms of how they sound, how they function, & what they actually are...melodic & harmonic tonal material, the territory.
Take note of the octave shapes. Memorize octave shapes!
These are the same 5 tones can be called by 2 names. With C Major, we are calling the C the Root of the system.
The flats (b) refer to what is different from A Major through comparing or paralleling. A's 'normal' 3 is C#, so A's b3 (lowered 3rd) is C. Likewise, A's 'normal' 7 is G#, so A's b7 (lowered 7th) is G.
There aren't any flats in the C's formula because it is Major, & Major is our point of comparison. If we wanted parallel C minor Pentatonic to C Major Pentatonic, we get: C is 1, Eb = b3, F = 4, G = 5, Bb = b7.
From the D, the scale is
called the Vietnamese Scale (R 2 4
From the E, the scale is called the Malkos Raga (R b3 4 b6 b7).
From the G, the scale is called the Bac Scale (R 2 4 5 6).
Memorization can work in a number of ways: by shapes, by octaves, by repetition, &/or from getting to know the scale system in as many ways as possible.
We could start with memorizing frame 1. Memorize the shape & how it is played. Play it until we know it. Play it a whole bunch, getting the feel of it. The shape of it.
Then, play it 10 times, but change the focus. One of these foci will be the naming of tones. Keep playing it, but change what we are paying attention to as we play the scale. Paying attention could mean something technical, or mental, or feeling-oriented, or listening.
Say the names of the tones as you play them.
Play all the single tones within the scale. Ask what are all the A's in the scale? All the D's?, etc.
Ask...what are all the tones of the borders? And, how are the same tones played in the next frame?
For string sets 6/5, 5/4, 4/3, & 2/1: to find an identical tone (unison) on the lower of the set of 2 adjacent strings (i.e. 6/5 - 6 being the lower), move up 5 frets (not including reference tone).
For strings 3/2, move up 4.
When we take a close look at the guitar scales above, we will see how these rules are always true, & the same tones are simply being refretted in different positions.
The same rule applies in reverse (on 3/2, go down 4 to find the same tone on the higher string).
And finally, the rule applies in reverse for an octave: to find an octave on the lower string of 2 adjacent strings, move down 7 frets.
Up & down for the same tone (for all string sets except 3/2 - the unison on higher string is down 5 - the octave on higher string is up 7 - or opposite) for adjacent strings always equal 12.
Guitar scales could also be called tone groups or tone collections or tone families or nothing or whatever else makes sense to us.