Which of the following intervals can correctly be described as 'perfect'?
AMajor sixth
BMinor third
CAugmented second
DPerfect fourth
Only unisons, fourths, fifths, and octaves belong to the 'perfect' quality family. Seconds, thirds, sixths, and sevenths are classified as major or minor (and can be augmented or diminished). Describing a fourth as 'major' or a third as 'perfect' is a category error — the quality systems for these two groups do not overlap.
Question 2 True / False
A major second is larger than a minor third because major intervals are typically bigger than minor intervals of any number.
TTrue
FFalse
Answer: False
A major second is 2 half steps; a minor third is 3 half steps — so the major second is actually smaller. Major and minor qualities only compare intervals of the *same* number: a major third (4 half steps) is larger than a minor third (3 half steps), and a major sixth is larger than a minor sixth. But you cannot use major/minor to rank intervals of different numbers against each other.
Question 3 Short Answer
What distinguishes an augmented interval from a diminished interval, and how are they related to major, minor, and perfect intervals?
Think about your answer, then reveal below.
Model answer: An augmented interval is one half step larger than the major or perfect version of that interval number; a diminished interval is one half step smaller than the minor or perfect version.
For example: a perfect fifth is 7 half steps, so an augmented fifth is 8 and a diminished fifth is 6. A major third is 4 half steps, so an augmented third is 5; a minor third is 3 half steps, so a diminished third is 2. Augmented and diminished are extensions of the quality system beyond its major/minor/perfect core, used when enharmonic spelling requires a different name for the same pitch distance.