Dorian and Mixolydian: Modes from the Major Scale

I always start this at the blackboard with just the white keys — because you already know everything you need. Look at C major: C D E F G A B. That sequence of whole steps (W) and half steps (H) spells out W W H W W W H. If you call C home, you get Ionian — the ordinary major scale. But watch what happens when I circle the D and call that home instead. Play D E F G A B C D — same seven white keys, nothing added or removed. Now the step pattern reads W H W W W H W. That new pattern is called Dorian. Notice the minor third (the H comes early, between E and F) — so it sounds minor. But the sixth is a whole step above the fifth, which is larger than in natural minor. That raised sixth is what gives Dorian its distinctive open, bittersweet quality. Think of the folk ballad 'Scarborough Fair' — that luminous-but-melancholy character is Dorian. Now circle the G and make that home: G A B C D E F G. Step pattern: W W H W W H W. That is Mixolydian. It sounds bright and major-flavored because it still has a major third (B is four semitones above G). The difference from plain major is the seventh: F is one semitone lower than you would expect in G major (where it would be F-sharp). That lowered seventh gives the scale a slightly unresolved, open-ended drive — exactly the sound you hear in blues-rock and Celtic fiddle tunes. If you ever get stuck and cannot remember which mode you are in, count the whole steps and half steps from the tonic up to each note. The step pattern is your fingerprint: W H early means Dorian; W W H with the late lowered seventh means Mixolydian. That counting strategy will never let you down.