Observing the characteristics of the notes of a scale, we can say that the VII° assumes the role of sensitive, which means it has to conclude the sequence on its root (seen as VIII°). This happens when the VII° is found a half-step from the root. In the NMS, however, the distance between the VII° and the VIII° is one step, and therefore loses the role of sensitive. For this reason, in the past centuries, composers opted to raise the VII° of the NMS to 1st, creating the Minor Harmonic Scale (abbreviated to MHS).
When comparing the NMS to the MHS we notice that the difference is only in the VII°, which is raised to 1st. Lets look at the natural minor and the minor harmonica scales of A.

We can also compare the MDS of A with the MHS of A. We notice that the III° and the VI° of the major scale are lowered to 1st in the Minor Harmonic Scale.

Build the minor harmonic scales of all the scales and compare the sequences in the special table.

In the past centuries, composers noticed that the step and a half interval that was created between the VI° and the VII° of the MHS was too high for the intonation of the human voice: they therefore decided to raise the VI° to 1st, creating a new scale called the Minor Melodic Scale (MMS). In this scale, the VII° note is always sensitive, because it is found a half-step from the root. The composers also decided that the sensitive note (which is the VII°) no longer needed the 1st between this and the root. Therefore the MMS, in descending sense, has the same notes as the NMS of the same scale, as we can see in the example, which indicates the ascending and descending minor melodic scale of A:

Bach took advantage of the minor melodic scale by maintaining the alterations in a descending sense. Here is the Bach Scale:

In modern music, the minor melodic scale is also maintained in a descending direction (the same system already adopted by Bach), and is called the Minor Melodic Jazz Scale, or Real Minor Melodic, even if for convention it is simply called the Minor Melodic Scale. Therefore when talking about the MMS in modern music, it has a sequence of evenly spaced intervals, even when descending.
Comparing the NMS with the MMS of A, we notice that in the MMS the VI° and the VII°s are raised to 1st.

Comparing the MDS of A with the MMS of A, we see that the only difference is in the III°, which is lowered to 1st in the minor melodic scale.
I recommend that you practice the construction for the minor melodic scale, then checking your results in the appropriate table.

Top of page

Print