In this lesson, I'm going to assume that you've already covered the construction of major scales, and at least one of the basic shapes. So... the form most everyone learns first is this one:
Shape 1: Major Scale
--|-1-|-2-|---|---|---|---
--|---|-2-|---|-4-|---|---
--|-1-|---|-3-|-4-|---|---
--|-1-|---|-3-|-4-|---|---
--|-1-|-2-|---|-4-|---|---
--|---|-2-|---|-4-|---|---
The "|" mark frets. The numbers mark fingers--not frets--because all these shapes are moveable. The bold numbers mark roots of the current scale. If you drop two notes(the 4th and 7th), you're left with the major pentatonic scale. I've put the 4th's and 7th's in parentheses. Extra notes marked with "*".
Pentatonic Shape 1: Based on Major/Ionian
--|(7)|-1-|---|*2*|---|---
--|---|-5-|---|-6-|---|---
--|-2-|---|-3-|(4)|---|---
--|-6-|---|(7)|-1-|---|---
--|-3-|(4)|---|-5-|---|---
--|---|-1-|---|-2-|---|---
Just like there are 5 notes to the pentatonic scale, there are 5 shapes:
Pentatonic Shape 2: Dorian
--|---|-2-|---|*3*|(4)|---
--|---|-6-|---|(7)|-1-|---
--|-3-|(4)|---|-5-|---|---
--|(7)|-1-|---|-2-|---|---
--|---|-5-|---|-6-|---|---
--|---|-2-|---|-3-|(4)|---
Pentatonic Shape 3: Phrygian (If you start on the 4, this shape is Lydian
--|-3-|(4)|---|*5*|---|---
--|(7)|-1-|---|-2-|---|---
--|-5-|---|-6-|---|---|---
--|-2-|---|-3-|(4)|---|---
--|-6-|---|(7)|-1-|---|---
--|-3-|(4)|---|-5-|---|---
Pentatonic Shape 4: Mixolydian
--|---|-5-|---|*6*|---|---
--|---|-2-|---|-3-|(4)|---
--|-6-|---|(7)|-1-|---|---
--|-3-|(4)|---|-5-|---|---
--|(7)|-1-|---|-2-|---|---
--|---|-5-|---|-6-|---|---
Pentatonic Shape 5: Minor/Aeolian
--|---|-6-|---|(7)|*1*|---
--|---|-3-|---|(4)|-5-|---
--|(7)|-1-|---|-2-|---|---
--|---|-5-|---|-6-|---|---
--|---|-2-|---|-3-|(4)|---
--|---|-6-|---|(7)|-1-|---
This last shape is the most common one, because the blues scale is based on it.
/ my profile 
