piano scale
C natural minor
C1D2E♭♭3F4G5A♭♭6B♭♭7
The major scale started from its sixth degree: same seven notes, a different centre of gravity.
Written out
Every accidental is written in, rather than left to a key signature, so the letters can be read one at a time.
The step pattern
CWDHE♭WFWGHA♭WB♭WC
What is true of it
C natural minor is C, D, E♭, F, G, A♭ and B♭, and back to C.
Its steps are W – H – W – W – H – W – W, where W is a whole step and H a half.
On the same tonic, C harmonic minor differs from it by exactly one note.
Chords made only of these notes
CmminorCm7minor seventhDdimdiminishedDm7♭5half-diminished seventhE♭majorE♭maj7major seventhFmminorFm7minor seventh
Found by testing every chord in the catalogue against these 7 sounds, not chosen.