Minor Scales

                 A scale is a consecutive listing of the 7 pitches within a diatonic key.  Practicing scales is an effective way to commit the 7 pitches of a given key signature to memory.  Every diatonic key signature results in one major and one minor tonic.  In our previous lesson we discussed the scales that result from major tonics.  Today we will discuss minor tonics and the scales that they create. 

       The scale that is formed by applying a given key signature to its minor tonic is a natural minor scale.  These scales are classified as natural minor because of the intervals formed between the tonic and each of the other pitches.  Both major and minor scales contain a perfect 4^th and 5^th.  However, the 3^rd, 6^th and 7^th intervals of a natural minor scale are all minor in quality.  The only major interval in a natural minor scale is the 2^nd.    

                This sequence of major 2^nd, minor 3^rd, perfect 4^th, perfect 5^th, minor 6^th and minor 7^th from the tonic can be used to determine the pitches of any natural minor scale.  Another way to determine the pitches of a natural minor scale would be to use one’s knowledge of the circle of fifths.  The circle of fifths lays out the keys signatures of every minor tonic by either increasing sharps or flats.  There are many diagrams of the sharp and flat key signatures available in literature and on the internet.  A musician can determine the pitches of a natural minor scale by starting on the tonic and applying the given key signature of that key while ascending or descending in stepwise motion until he/she reaches the repeat of the tonic in the next register.

                A third way to determine the pitches of a natural minor scale is to examine the whole and half step relations from pitch to pitch within the scale.  Natural minor scales are composed of this set pattern of whole and half steps: W-H-W-W-H-W-W.  This pattern can be broken into a dorian (W-H-W) and phrygian (H-W-W) tetrachord that are connected by a whole step.  Since the two tetrachords differ, this method of realizing the pitches of a natural minor scale is not as popular.

                Beside the natural minor scale, there are two other versions of minor scales.  The harmonic minor scale is a variation in which the seventh pitch is raised a half step.  This causes the seventh pitch to be a half step away from the tonic and act as a leading tone.  In harmonic context, this leading tone is used in dominant chords to lead back to the tonic.  Without it there is no sense of urgency to resolve to the tonic.

                However, raising the seventh tone causes the distance between the sixth and seventh pitches to be an augmented 2nd.  This distance creates a melodic quality that is reminiscent of Middle Eastern culture.  It is a very specific and often undesirable melodic quality.  To avoid this sound, the melodic minor scale was created.  In this scale, the sixth and seventh pitches are raised while ascending the scale.  When descending, these pitches are returned to normal and the scale is identical to natural minor.  There is only a need for a leading tone when the seventh travels up to the tonic, so the scale is only altered when the melodic motion is ascending.

                Musicians can employ many methods when practicing scales.  We should realize the specific focus we wish to instill in our playing and use a method that supports that skill.  I listed several methods in my last lesson on major scales.  The same methods can be used to practice natural minor scales.  After these are learned, they can be varied accordingly to create harmonic or melodic minor scales.  One can choose to cycle through all the keys of a certain type of minor scale, or cycle through the tree types before changing keys.  The possibilities are numerous.