> they also have a starting point Indeed. For anyone that is not sure about that, take a piano (like this virtual one[1]) and play a scale of all the white not

> they also have a starting point Indeed. For anyone that is not sure about that, take a piano (like this virtual one[1]) and play a scale of all the white notes starting with C. The play a scale of all those same white notes, but starting with A. You should immediately notice that the second version is in a minor key (sounds "sadder"). 1: http://virtualpianos.info/ http://virtualpianos.info/