Questions: Chord Quality Identification by Ear

Question 1

A diminished triad is built from which combination of stacked intervals?

• A. A minor third and a perfect fifth (m3 + P5)
• B. Two minor thirds (m3 + m3)
• C. A major third and an augmented fifth (M3 + A5)
• D. A minor third and a major third (m3 + M3)

Answer: (B)

A diminished triad stacks two minor thirds: root to the third is a minor third (3 semitones), and the third to the fifth is another minor third (3 semitones), giving a diminished fifth overall. This double compression creates the tense, unstable sound. By contrast, a minor triad is m3 + M3 (option D), giving a perfect fifth.

Question 2

You is expected to know the root note of a chord in order to identify its quality by ear.

• T. True
• F. False

Answer: False

Chord quality is an intervallic property that is the same regardless of which pitch the chord is built on. A major triad sounds the same characteristic bright, stable color whether it is C major or F# major. Identifying quality means recognizing the interval relationships between the notes, not their absolute pitch.

Question 3

When first learning to identify chord quality by ear, which interval within the triad should you focus on first, and why?

Model answer: The third (major vs. minor third), because it is the primary determinant of the chord's overall color — major third produces the bright/stable feeling of major quality, minor third produces the darker feeling of minor or diminished quality.

The third is the most perceptually salient distinguishing feature. Once you can reliably hear major vs. minor thirds, you can distinguish major from minor and diminished from augmented. The fifth then helps differentiate within those groups: diminished has a compressed (diminished) fifth versus the perfect fifth of minor; augmented has a stretched (augmented) fifth versus the perfect fifth of major.