Minor Scale

Minor scale

A minor scale in Western music theory includes any scale that contains, in its tonic triad, at least three essential scale degrees: 1) the tonic (or name of the scale), 2) a minor-third, or an interval of a minor third above the tonic, and 3) a perfect-fifth, or an interval of a perfect fifth above the tonic, altogether comprising a minor triad on the tonic note. All minor scales differ from major scales in that the third in major scales is a major third, i.e. one semitone higher than the minor third found in minor scales. In other words, the third scale degree in all minor keys has been lowered one half step, or semitone.

• http://en.wikipedia.org/wiki/Minor scale