Confusion about major and minor second intervals?

Question

Why is a major second interval different from a minor second interval considering that in the natural scales formulae they are both one whole step?

Answer 1

The term minor has more than one meaning as it relates to keys/scales versus intervals. You cannot simply look at the distance between the notes in a given scale to determine the name of the interval. Allow me to explain.

C D E F G A B C is a C-major scale

C D Eb F G Ab Bb C is a C-minor scale

So, you are correct that C-major and C-minor have some intervals in common, and that C to D is common to both scales. C to D is a major second (or a whole step) regardless of what key one is in.

C to F is a perfect fourth in both keys – it is not a major fourth in C and a minor fourth in C minor. The interval is always a perfect fourth. Similarly, C to Bb is not a minor seventh; it is a dominant seventh.

To make your life easier, let's look at all ascending intervals from C to C.

C to C# (or Db) is a minor second. As Glenn B. noted in an earlier reply, this is also called a half-step.

C to D is a major second or a whole step.

C to Eb is a minor third.

C to E is a major third.

C to F is a perfect fourth

C to F# is an augmented fourth; C to Gb is a diminished fifth

C to G is a perfect fifth

C to Ab is minor sixth; C to G# is an augmented fifth

C to A is a major sixth

C to Bb is a dominant seventh; C to A# is an augmented sixth (very rare)

C to B is a major seventh

C up to C is a perfect octave

I hope this helps.

Answer 2

Answer 3

Actually, the minor 2nd is considered a half step.