GUITAR SCALES AND HOW THEY WORK

SCALES ARE MOVEABLE

Any scale, or mode, for that matter, are built on intewrvals, or the distance beween notes.  On a fretboard, these intervals are called steps.  A half step is equal to the distance of one fret space.  A whole step is equal to the distance of two fret spaces.    This is why scales are moveable, meaning you can move the entire scale shape up or down the fretboard, and move the shape from one key to another, and the intervals between the notes stay the same.  Here is an example of the minor pentatonic scale in the key of A;
e____________________________________________5___8___
b____________________________________5___8___________
g____________________________5___7___________________
d____________________5___7___________________________
a____________5___7___________________________________
e____(5)__8___________________________________________

Now compare the distance or intervals between notes on this scale in the key of a to the same scale, but now in the key of G below.

e_____________________________________________3___6___
b_____________________________________3___6___________
g_____________________________3___5___________________
d_____________________3___5___________________________
a_____________3___5___________________________________
e____(3)___6___________________________________________

It is the exact same distance between notes, we simply moved the shape of the scale - and this is how you move a scale from key to key anywhere on the fretboard.  It doesn't matter what the scale is, they are moveable, just like this one.  This is why you will sometimes hear someone say, once you learn one scale, you have learned 12 scales.  From the open position at the nut to the 12th fret, you have 12 different keys you play any given scale in, simply by sliding the shape around.  From the 12 fret up to the body of the guitar all your notes along the fretboard simply repeat themselves, one octave higher.  Pluck the low e (thick string) without fretting the string, you have an E note.  Fret the same string at the 12th fret, you have the same E note, one octave higher.

On the first example above, on the scale you will notice the note (5).  This is the root note of that scale, the 5th fret of the low E string being an A note makes the scale an A minor pentatonic.  On example 2, the scale shape was moved, and the new root note became (3), or G minor pentatonic, since the note at the 3rd fret of the low E string is a G note.  Sometimes you will see these referred to as box positions.  The A note of the minor pentatonic scale is located on the 5th fret, so this would be considered  the 5th position, or 5th box position.  The G root note is located on the 3rd fret, so this now becomes the 3rd position.

It's often times called playing within a box because of the distance or intervals between all the notes within that scale shape.  All the notes can be easily reached without having to move or slide your hand up or down the fretboard.  The only problem with playing within a box position is that over time, as you advance as a player, it becomes limited as to what you can do in such a small area of the fretboard.  This is where long scales can come into play.  They contain the same notes as the box positions, but they cover a much wider range of the fretboard.  And yes, long scales are moveable as well.  Here is an example of the A minor pentatonic scale in the key of A, long version.

e____________________________________________10__12__15__17__
b_________________________________8__10__13__________________
g__________________________7__9______________________________
d_______________5__7__10_____________________________________
a_________5__7_______________________________________________
e__(5)__8_____________________________________________________

Now here is the same moveable scale but now in the key of G

e______________________________________________8__10__13__15__
b___________________________________6__8__11__________________
g____________________________5__7_____________________________
d__________________3__5__8____________________________________
a___________3__5______________________________________________
e____(3)__6____________________________________________________

As you can see, long scales really do open up the fretboard, but they do take longer to learn.  And with long scales, you now have to move your fretting hand up and down the neck as you move from note to note.  One way to move around quickly within a long scale is to slide up to some of your notes.  Just as a quick example, you could take the notes on the B string, and pluck the 6th, slide up to the 8, and hammer onto the 11.

GUITAR SCALES AND HOW THEY WORK

For the serious and more advanced player, even long scales become limiting, and they want a little added color or tone to the scale.  Many dress up a scale, and there are many ways of doint this.  One way is to take two scales and mix some of the notes together, to come up with a completely new scale, their own creation.  But if you are not that advanced or simply starting out, the better route would be to do a much easier dressing up of a scale by simply adding one, maybe two notes from outside the scale you are using.  Which notes to add?  That is where being creative comes into play, and different players will add different notes.  Use this as your rule - if you play your scale with the added note and it sounds good, then go with it.