Watch the Dorian online guitar lesson by TrueFire from The Indispensable Toolbox for Guitarists
Dorian - Introduction is a video guitar lesson presented by Chris Buono and is sourced from Modes That Matter.
As you're about to see the modes are much more than just scales starting on specific degrees of their parent scales. Every mode has a color unto itself that can be used by you to paint myriad audio images. While this course will examine each mode through its relationship to whatever parent scale from which it came, the real bread & butter is in the mode's own formula. Let's start with Dorian.
The Dorian mode is the second mode of the diatonic modal system also known as the "church modes". Therefore it's built on the second degree of the parent major scale, which in this case is referred to as the Ionian scale. In order for Dorian to be part of the system the notes have to be exactly the same as the parent major scale's notes. To do that a major built on the 2nd degree of the parent scale will have its 3rd and 7th degree lowered a half step. The resultant formula is as follows: 1 2 b3 4 5 6 b7.