Minor Scale - Finding Key Signatures

Finding Key Signatures

Major and minor keys that share the same signature are relative to each other; so C major is the relative major of A minor, and C minor is the relative minor of E♭ major. The relative major is a minor third above the tonic of the minor. For example, since the key signature of G major has one sharp (see major scales for how to find this), its relative minor, E minor, also has one sharp in its key signature.

Music may be written in an enharmonic scale (e.g. C♯ minor, which only has four sharps in its key signature, compared to the theoretical eight flats required for D♭ minor). The following are enharmonic equivalents:

Key sig.	Major scale	Minor scale
5♯/7♭	B/C♭ major	g♯/a♭ minor
6♯/6♭	F♯/G♭ major	d♯/e♭ minor
7♯/5♭	C♯/D♭ major	a♯/b♭ minor

Double sharps/double flats can be written as accidentals, but not as part of a key signature. For example:

D♭ minor key signature: E♭ + A♭ + D♭ + G♭ + C♭ + F♭ + B (the B is now double flatted and therefore, notated after the single accidentals, which obviously do not include the B♭)

D♭ natural minor = D♭ E♭ F♭ G♭ A♭ B C♭ D♭

D♭ melodic minor (ascending and descending) = D♭ E♭ F♭ G♭ A♭ B♭ C D♭ C♭ B A♭ G♭ F♭ E♭ D♭

D♭ harmonic minor = D♭ E♭ F♭ G♭ A♭ B C D♭