Originally posted by dev
what if i combine my A minor pentatonic scale with other notes to create dorian scale,now does the chord tonality changes for the notes in that scale(dorian)

Not to confuse you anymore, but the actual answer to that question would be yes & no. Lets start w/the no;

It is a common thing w/rock & blues guitarists to borrow notes from the dorian when creating with a pentatonic scale. David Gilmour (Pink Floyd, Another Brick in the Wall pt.2) and Santana (Black Magic Woman) are good examples of this, Slash (G&R) does this a lot too. So just because you slip in a couple of notes from the Dorian does not mean you have to change your chord progression.

A dorian scale, on the other hand is not as flexible as a Pentatonic scale. A dorian scale is actually derived from a Major scale. Ex: C maj. (C D E F G A B C) D dorian (D E F G A B C D) starting and stopping on the 2nd degree. So if your gonna write a riff or melody using a dorian scale you have to take the chords that appear within the major scale harmony into consideration. Here's an ex. using A dorian/G major;

Harmony (chords) that exist within a G maj. scale
G A- B- C D E- F# diminished

Jazz alta is trying to give you a simplier way of looking at things (which I totally agree with) But sometimes with this stuff it's better to at first learn it as in depth as possible then form your own veiw of how to apply it in a practical sense. Good luck