piano scale
B♭ harmonic minor
B♭1C2D♭♭3E♭4F5G♭♭6A7
Natural minor with the seventh raised, which buys a leading note and pays for it with a step and a half between the sixth and seventh.
The same sounds spelled from the other side are A♯ harmonic minor.
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
B♭WCHD♭WE♭WFHG♭W+HAHB♭
What is true of it
B♭ harmonic minor is B♭, C, D♭, E♭, F, G♭ and A, and back to B♭.
Its steps are W – H – W – W – H – W+H – H, where W is a whole step and H a half.
On the same tonic, B♭ natural minor differs from it by exactly one note.
Chords made only of these notes
CdimdiminishedCm7♭5half-diminished seventhD♭augaugmentedE♭mminorE♭dimdiminishedE♭m7minor seventhE♭m7♭5half-diminished seventhFmajor
Found by testing every chord in the catalogue against these 7 sounds, not chosen.
Other scales on B♭
C harm minC♯ harm minD♭ harm minD harm minD♯ harm minE♭ harm minE harm minF harm minall 374