The Blues Scale
The blues scale is a minor pentatonic scale with an added note. It's not really considered a six-note scale because the added note is considered a passing tone; you use it to get from one note in the scale to the next note smoothly. The added note has gained acceptance over the years, and the five notes with the passing tone have grown into their own scale—the blues scale.
FIGURE 5-10 is an example of an A-minor blues scale.
Notice how the shape is the same as the minor pentatonic scale; you just add the note E to the scale. The E helps smooth out the jump between the D and the E normally found in the minor pentatonic scale. The passing tone of E has long been used by singers and is another way that vocalists have influenced instrumental soloists. You can use the blues scale in place of a normal minor pentatonic scale—they substitute for each other. The added E is a very bluesy note and will add spice to your original scale. You don't have to play the blues to use the scale; many rock players find it effective in rock solos.
“Hexa” means “six,” so it stands to reason that a hexatonic scale is a six-note scale. Many players find that by adding one note to the pentatonic scale, they can yield some incredibly fresh sounds. Let's go back to the original A-minor pentatonic scale that contains the notes A, C, D, E, and G. To make this pentatonic scale into a hexatonic scale, you add the note B. FIGURE 5-11 is the new hexatonic scale in A.
Adding one note changes a lot doesn't it?
Now for a Little Theory
We added the note B. While that's the “name” of the tone, knowing the name of the note only helps us in one key. For instance, what note do you add to an F-minor pentatonic scale to make it hexatonic? You could move the A-minor example to F and figure it out, but that's taking the long way home. Music theory uses numbers to designate the distance between notes. The term for this distance is an interval. The interval from A to B is simply a second. (There's more on this in Chapter 7.)
We call it a second because the distance from A to B is two; B is the second note of an A scale. Seconds are also always two frets above any note. Just as A is the fifth fret, B is the seventh fret. No matter where you are on the guitar, seconds are always two frets above the root. So what I'm really saying is that the hexatonic scale is a minor pentatonic scale with an added second. If we call it a second, it can apply to any key and any scale.