The Melodic Minor Scale
The melodic minor scale is unlike the natural minor scale because the pitches are different depending on whether the scale is ascending or descending. When the scale is ascending, the pattern of whole steps and half steps is as follows:
1 W 2 H 3 W 4 W 5 W 6 W 7 H 8
Descending, the melodic minor scale is the same as a descending natural minor scale:
8 W 7 W 6 H 5 W 4 W 3 H 2 W 1
Like the natural minor scale, the melodic minor is a diatonic scale. No letter names will be repeated or skipped. Here is a simple step-by-step process to create melodic minor scales accurately, with the G melodic minor scale as an example.
1. Write all of the scale degrees under the staff, both ascending and descending.
2. Write the pattern of whole steps and half steps as they occur between each scale degree:
(1 W 2 H 3 W 4 W 5 W 6 W 7 H 8 and then 8 W 7 W 6 H 5 W 4 W 3 H 2 W 1).
3. Write in the pitches for the diatonic scale. Start on the note G and write each successive note for each scale degree. Do not skip any pitches and do not repeat any pitches. Make sure that scale degree 8 is exactly one octave above the first note of the scale. Also, the last note should be exactly the same as your first note, so in this case your last note should be G.
4. Check every whole step and half step in the scale and write in the appropriate accidentals. By going through each whole step and half step we can complete the melodic minor scale. Remember to include all accidentals. You must write the natural sign in front of the F in the descending section of the G melodic minor scale; otherwise it will be interpreted as an F sharp because that was written for the ascending part of the scale. It is good practice to always include accidentals for scale degrees 6 and 7 for the descending part of the melodic minor scale.
Things to remember and check:
The first and the 8th scale degree of the melodic minor scale should be exactly the same pitch an octave apart. For example, if your first pitch is a G, and your 8th scale degree is G sharp, an error has been made. Also, when you get back to scale degree 1 at the end of the scale, make sure that it is also G.
Unlike the major and natural minor scales, it is possible to have sharps and flats in the same melodic minor scale. For example, in the G melodic minor scale we have both a B flat and an F sharp.