Which mode begins on the first degree of the major scale and has a pattern of semitones between 3-4 and 7-8?

• A. Ionian mode
• B. Aeolian mode
• C. Dorian mode
• D. Phrygian mode

Answer: (A)

Modes are scales formed by starting on different degrees of the major scale. The one that begins on the first degree and has a semitone between the third and fourth notes and another between the seventh and eighth notes is the Ionian mode, which is the major scale itself. This specific pattern—whole, whole, half, whole, whole, whole, half—produces those two semitone steps at 3–4 and 7–8, identifying Ionian. The other modes start on later degrees and place the half steps in different spots (for example, starting on the second, third, or sixth degree shifts where the semitones occur), so they don’t match the 3–4 and 7–8 pattern.