Answer:
1.The melodic minor scale has half steps between scale degrees 2-3, and 7-8 when ascending. The melodic minor scale reverts to natural minor when descending. The major scale has half steps between scale degrees 3-4, and 7-8.
2.Harmonic minor scale -- a form of a minor scale with half steps between 2-3, 5-6 and 7-8. Its unique interval is that between 6-7 -- the whole plus half step (or augmented 2nd). It can be thought of as a natural minor scale with a raised 7 scale degree.
3.The harmonic minor scale has half steps between scale degrees 2-3, 5-6, and 7-8. (It is the only one of the three minor scales with a step and a half between scale degrees 6-7.) The melodic minor scale has half steps between scale degrees 2-3, and 7-8 when ascending.
