Minor & the relative relationship

Play the same major scale but start on its sixth note, and it no longer sounds bright — it sounds dark. Not a single new note, just a different starting point.

The dark version is called minor. Major and its corresponding minor consist of the same seven notes and differ only in which note is felt as the root. C major and A minor share the same supply note for note; one organizes itself around C, the other around A. They are relative to each other — two perspectives on the same collection.

Why does the effect change if the notes stay the same? Because the distances to the root change. From A, the third note sits a half step lower than it does from C, and that minor third instead of a major third produces the darker character. The entire minor quality rests on one distance shifted by a half step.

This section is also the transition to harmony: the idea that the same notes get organized around a root becomes the concept of key.