In music theory, melodic mode and harmonic mode have unique rules. The characteristic of melodic major is that when ascending, the scale is completely consistent with the natural major, and when descending, only the sixth and seventh notes of the natural major are lowered by a semitone. In specific operations, for example, when recording the scales of C major and A minor, starting from the natural major, the harmonic major will lower the 6th level on this basis; on the contrary, when the melodic minor ascends, the 1st level of the natural minor will be lowered. The second and second degrees are raised a semitone, and the descending notes remain the same. Just remember the rules of the natural minor. Medieval modes such as C Ionian, D Dorian, etc. are also divided based on a specific basic scale CDEFGAB. In general, the changes in the melodic mode lie in the specific processing of ascending and descending pitch levels, while the harmonic mode is adjusted based on the natural mode. Understanding these formulas will help you quickly master the conversion and application of modes.