We can think about B minor as B major with a lowered 3rd note, a lowered 6th note, and a lowered 7th note, but this can be a lot of information to think about when we're trying to play music. So instead, we can think about it as a D major scale, starting on the 6th note, B. So let's refresh ourselves on the D major scale. We play our open D, E, 2nd fret, F#, 4th fret, open G, A, 2nd fret, B, 4th fret of the G string, C#, 6th fret, and now D on the 7th fret. If we go back to the 6th note of the scale, we get to B. Now we can play the same scale, D, starting on B, and we'll get our B minor scale - B, A, G, F#, E, D, C#, and B. This is what the scale sounds like... and that's the B minor scale, on the bass guitar.