A minor is a minor scale based on A, with the pitches A, B, C, D, E, F, and G. Its key signature has no flats and no sharps. Its relative major is C major and its parallel major is A major.
In modern notation, the key signature for music in a minor key is typically based on the accidentals of the natural minor scale, not on those of the harmonic or melodic minor scales. For example, a piece in E minor will have one sharp in its key signature because the E natural minor scale has one sharp (F♯).
