Scales of the World
The Melodic Minor differs from the Natural Minor in that the seventh tone is sharpened when ascending.
This scale has a dark, somber sound on the lower notes and a resolving, “melodic” sound on the highest few notes. The scale is played as the Natural Minor when descending. Strange but true.
Historically, the Melodic Minor scale was conceived, much like the Harmonic Minor scale, in order to solve a harmonic “problem”.
The “problem” in this case was that the step and a half gap at the top of the Harmonic Minor scale was viewed as unacceptably large when composing melody lines. Composers raised the sixth of the Harmonic Minor Scale to create the Melodic Minor Scale, which basically just makes it a major scale on top.
This scale is quite nice as well, though, and ’tis a fine alternative to the Natural Minor or the Pentatonic Minor.
Be careful with the 6th and major 7th, as they will clash with the flat 6th and 7th of the natural minor.
Use these in passing phrases if necessary.