Scales refer to a series of notes that go in an ascending and descending manner. The notes of the minor scale, unlike the notes on a major scale that sound bright and cheerful, sound solemn and sad.
In music theory, minor scale may refer to the natural minor, harmonic minor, and melodic minor scales. A minor scale differs from a major scale in that the third degree in a major scale is a major third (four semitones) above the first degree. In other words, the third degree in a major scale is one semitone higher than in a minor scale. When a major scale and a natural minor scale have the same key signature, they are relative keys. A natural minor scale has the same notes as its relative major scale, but is built starting from the sixth note of the relative major scale. A harmonic minor scale differs from a natural minor scale in that the seventh note is raised one semitone. Melodic minor scales raise both the sixth and seventh notes one semitone when ascending, but when descending, the sixth and seventh notes are flattened, producing the natural minor scale.