Which mode has half steps between 3-4 and 7-8 and begins on the first degree of the major scale?

Which mode has half steps between 3-4 and 7-8 and begins on the first degree of the major scale?

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

Answer: (B)

This question tests recognizing the Ionian mode, which is the major scale, by where the half steps land. The major scale has the interval pattern of whole, whole, half, whole, whole, whole, half. That means the semitones occur between the third and fourth degrees and again between the seventh and eighth degrees. Since the mode in question begins on the first degree of the major scale, those semitone pairs happen exactly between 3–4 and 7–8, identifying it as the Ionian mode. The other modes start on different degrees, so their semitone placements shift: Dorian has semitones between 2–3 and 6–7; Phrygian between 1–2 and 5–6; Locrian between 1–2 and 4–5.

This question tests recognizing the Ionian mode, which is the major scale, by where the half steps land. The major scale has the interval pattern of whole, whole, half, whole, whole, whole, half. That means the semitones occur between the third and fourth degrees and again between the seventh and eighth degrees. Since the mode in question begins on the first degree of the major scale, those semitone pairs happen exactly between 3–4 and 7–8, identifying it as the Ionian mode.

The other modes start on different degrees, so their semitone placements shift: Dorian has semitones between 2–3 and 6–7; Phrygian between 1–2 and 5–6; Locrian between 1–2 and 4–5.