relative key

Circle of fifths showing major and minor keysIn music, relative keys are the major and minor scales that have the same key signatures (enharmonically equivalent), meaning that they share all of the same notes but are arranged in a different order of whole steps and half steps. A pair of major and minor scales sharing the same key signature are said to be in a relative relationship. The relative minor of a particular major key, or the relative major of a minor key, is the key which has the same key signature but a different tonic. (This is as opposed to parallel minor or major, which shares the same tonic.)

For example, F major and D minor both have one flat in their key signature: B♭. Therefore, D minor is the relative minor of F major, and conversely F major is the relative major of D minor. The tonic of the relative minor is the sixth scale degree of the major scale, while the tonic of the relative major is the third scale degree of the minor scale. The minor key starts three semitones below its relative major; for example, A minor is three semitones below its relative, C major.