Major and minor in interval names simply mean bigger and smaller versions of the same interval type

The terms major and minor derive from Latin words for large and small. Applied to intervals, they describe the two sizes that non-perfect intervals (seconds, thirds, sixths, sevenths) can naturally take. A major second spans 2 semitones (a whole step); a minor second spans 1 semitone (a half step). A major third = 4 semitones; a minor third = 3 semitones. The same big/small logic extends to sixths and sevenths. Understanding this derivation prevents the common misconception that major/minor are mood labels — they are purely size labels at the interval level.

Examples

A to B = major second (whole step = big second). B to C = minor second (half step = small second). C to E = major third (4 semitones = big third). C to E-flat = minor third (3 semitones = small third).

Assessment

A student says ‘major intervals sound happy, minor intervals sound sad.’ Explain why this is a misconception at the interval level, using the major-second/minor-second example. Then give the semitone count for a major sixth and a minor sixth.