Which set lists the scale degrees for the major triad?

Which set lists the scale degrees for the major triad?

• A. 2, 3, 6
• B. 1, 3, 5
• C. 1, 2, 5
• D. 1, 4, 5

Answer: (D)

Understanding how a major triad is built is key: take the tonic as the root, then add the note a major third above, and the note a perfect fifth above. In scale-degree terms, those positions are 1, 3, and 5. For example in C major, C–E–G forms the C major triad. The set that lists these degrees is 1, 3, 5. Other sets wouldn’t match because they replace the third with a fourth, a sixth, or a second, which changes the chord quality or eliminates the defining third, so they don’t describe a standard major triad.

Understanding how a major triad is built is key: take the tonic as the root, then add the note a major third above, and the note a perfect fifth above. In scale-degree terms, those positions are 1, 3, and 5. For example in C major, C–E–G forms the C major triad. The set that lists these degrees is 1, 3, 5. Other sets wouldn’t match because they replace the third with a fourth, a sixth, or a second, which changes the chord quality or eliminates the defining third, so they don’t describe a standard major triad.