Chord Construction Theory (cont.)
If we take the C scale and start it on the second note of the scale, "D", but not altering any of the notes in the scale, we have what is called the Dorian mode. It's a completely different discussion to go into modes here, we will touch on some modes later, but we don't want to complicate things for now. The Dorian mode looks like:

(* = notes in a "D" minor chord)

Taking the first, third, and fifth notes of the Dorian mode gives us the D minor chord. To distinguish minor and major chords in the Roman numeral numbering system, I have the Major chords in capital letters (I), and the minor chords in small letters (ii). In the Arabic number system, I will put the letter "m" to indicate a minor chord, i.e. D minor would be either ii (I may for clarity even call the chord ii minor), or 2m.The next mode starts on "E":

(* = notes in an "E" minor chord, or iii or 3m chord)