The melodic descending minor scale is a primary heptatonic scale that can be built using the following steps between notes: 1, ½, 1, 1, ½, 1, 1.
The melodic descending minor scale is the same as the natural minor scale (the Aeolian mode of the primary heptatonic scale). One example of the scale is A, G, F, E, D, C, B. This example is shown below in traditional notation and in guitar tablature notation.
Up to the 20th century it was common to use the melodic ascending minor scale when going up and the melodic descending minor scale when going down, but more recently the melodic descending minor is commonly used in both directions.