Dorian

The notes

B C♯ D E F♯ G♯ A, then B. Compare with B natural minor, which has G natural: the G♯ is the raised sixth, and it is the entire difference.

Because the scale belongs to A major, a progression that pairs Bm with A or E is already dorian without any modal intention behind it.

On the fretboard

Seventh fret with the root on the low E string, or second fret with the root on the A. The seventh-fret position overlaps with the B minor pentatonic that most players use for solos.

The G♯ is the note to sound. Left out, the scale reverts to plain minor, and the listener hears a different piece of music over the same chords.

Where it is used

Rock and funk over a static Bm7, and modal jazz in the same setting. It also appears in folk-rock in D, where B minor is the relative minor and the sixth degree comes along naturally.

The mode is common on guitar precisely because B minor is a common chord in guitar keys — the scale arrives with the harmony rather than being chosen.

For a guitarist the practical point is that this mode requires no new shapes at all: the A major scale patterns already cover it, and the only change is which note the ear treats as home.