Minor Scales: Natural, Harmonic, Melodic

Natural minor follows its own whole/half-step pattern: W-H-W-W-H-W-W. Built on A, that's A-B-C-D-E-F-G-A — again all white keys. Every major key has a natural minor that shares the exact same key signature (the same notes, just starting and resting on a different note): this is the relative minor. C major and A minor are relatives; they use identical key signatures.

Careful with the terms in translation: English "relative minor/major" (same key signature, different tonic) is параллельный минор/мажор in Russian. English "parallel minor/major" (same tonic, different mode — C major and C minor) is одноимённый минор/мажор in Russian. The words swap meaning across the two traditions, so always check which pairing a text means.

Natural minor's 7th degree is a whole step below the tonic, so it doesn't pull toward it the way a major-scale leading tone does. Harmonic minor fixes this for cadences by raising the 7th degree a semitone, creating a real leading tone — at the cost of an unusual step-and-a-half gap between the 6th and raised 7th degrees, which gives harmonic minor its distinctive "exotic" sound.

Melodic minor solves that same problem more smoothly for melodic lines: ascending, it raises both the 6th and 7th degrees (removing the awkward gap); descending, it's conventionally played as natural minor again. Which form you use depends on whether you're voicing a cadence (harmonic) or writing a smooth ascending melodic line (melodic).