Which mode is defined as natural minor with a lowered second and fifth scale degree?

• A. Locrian
• B. Dorian
• C. Phrygian
• D. Lydian

Answer: (A)

Think in terms of how each mode alters the natural minor pattern. The Locrian mode is characterized by having the second and fifth scale degrees lowered. If you spell the notes from its tonic, you get 1, b2, b3, 4, b5, b6, b7. That means it is basically a natural minor scale with those two degrees flattened.

A concrete example helps: start on B in the C major scale to form the Locrian mode. You get B, C, D, E, F, G, A. Compare that with B natural minor (which would be B, C#, D, E, F#, G, A): the second note and the fifth note are lowered, exactly matching the description.

Other modes change different degrees (for instance, some lower the third and seventh, or raise the fourth), so they do not fit the idea of a natural minor with only the second and fifth flattened.