Minor Scales, in all various permutations, are one of the crucial components of Western music. Unlike their major counterparts, there are multiple scales for each Minor key, each with different interval spacing.
While the minor is more complicated than Major Scales, they are considerably less complex than more exotic scales like the Ragas or Hejaz scales, which contain intervals that can sound alien to those accustomed to Western music. As such, learning a minor key is typically considered a crucial part in a musician’s development.
The most basic form of a minor key is known as natural minor. In a natural minor scale, all of the notes within a minor key signature are played in a sequence. For instance, the A minor natural scale consists of A, B, C, D, E, F and G. In traditional music theory, this is known as an Aeolian mode.
Harmonic minors, notable for producing a slightly “Arabesque” sound, are created by simply raising the seventh note in the corresponding natural minor by one half step. As such, the A minor harmonic scale contains A, B, C, D, E, F sharp and G.
To play a melodic minor scale, one must raise the six and seventh notes of a natural minor by one half step while ascending, then revert to the natural minor as one goes back down. This means that the first half of an A minor melodic scale consists of A, B, C, D, E sharp, F sharp and G, while the second half is identical to a natural minor.
There are a number of other scales in a minor key that exist, but most Western musicians never familiarize themselves with them. However, some complex and experimental forms of jazz have been known to make use of more unconventional scales.
Various composers have expressed a preference for one type of minor key over the other. For instance, Mozart found the melodic minors helpful in crafting music, while some vocal composers saw the scale as incompatible with writing smooth melodies. For a sizeable proportion of musicians, knowing the theory behind the different types of minor key’s and the notes they incorporate is largely unnecessary. However, a working knowledge of each type of scale ensures that one has no trouble adopting to new key signatures or following rapid key changes in a jazz tune.
Unlike with Major scales, finding a song written completely within a single minor key can be difficult. However, songs in minor keys that utilize notes within such scales are commonplace. Examples of such include Grieg’s “In the Hall of the Mountain King,” Bill Withers’ “Ain’t No Sunshine,” and Thelonius Monk’s “Round Midnight.”