Minor scales

A minor uses the same seven white keys as C major, but starting on A turns the second step into a half step and lowers the third.

The natural minor pattern

Play the white keys from A up to the next A. The notes are those of C major, but the steps fall in a new order: W-H-W-W-H-W-W. This is the natural minor scale. Its half steps sit between degrees 2 and 3 (B to C) and 5 and 6 (E to F). The change you hear most is the third note: in A minor it is C, a half step lower than the C♯ of A major. Every minor scale has this lowered third. Minor keys are often, though not always, used for sad or dark moods.

Compared with the major scale on the same tonic, natural minor lowers three notes: the 3rd, 6th and 7th. C major is C D E F G A B; C natural minor is C D E♭ F G A♭ B♭. In movable-do solfège the lowered notes get their own syllables, me, le and te, in place of mi, la and ti, so a singer can tell from the syllable alone which version of the note is meant.

Harmonic minor: borrowing a leading tone

Natural minor has a weakness. Its seventh note is a whole step under the tonic (G under A), so the strong half-step pull you heard in major is missing. Composers fix this by raising the 7th by a half step, which gives the harmonic minor scale: A B C D E F G♯ A. Now G♯ leads up to A. The fix opens a gap of three half steps between F and G♯, and that gap gives harmonic minor its recognisable sound. The pattern is W-H-W-W-H-3H-H, where 3H means three half steps.

The raised seventh is never part of the key signature. A minor has no sharps or flats in its signature; the G♯ is written as an accidental each time it appears. Seeing the same accidental again and again, a half step under a likely tonic, is a strong clue that a piece is in a minor key.

Melodic minor: smoothing the gap

In a melody that runs up the scale, the three-half-step gap can sound awkward. The melodic minor scale raises the 6th as well as the 7th on the way up: A B C D E F♯ G♯ A, with the pattern W-H-W-W-W-W-H. Its top half matches A major. On the way down the raised notes are no longer needed, so the scale returns to natural minor: A G F E D C B A. Compared with major, ascending melodic minor lowers only the third.