Watch the Dorian online guitar lesson by Robbie Calvo from Modal Expose

The A major scale from B to B

Let's continue harmonizing the A major scale by building a chord from the second degree of the scale, the B note.
Here's the visual depiction of that - B C# D E F# G# A B. The bold notes are the notes that make up the chord B minor and B minor 7th. You can reference your chart to confirm this too.
Those single notes are, as we've said before, an arpeggio and constitute the strongest tones to resolve to over the B minor chords. Let's learn and play through a B minor 7th arpeggio in position over the chord backing track and you will hear how strong that sounds against the chord.

Now we'll overlay the B dorian mode over the B minor 7th chord and you'll hear that the chord, scale and arpeggio all have a 'tonal center' or resolution point of the 2nd chord. This is the second mode in the A major scale and is called B dorian.