piano scale
B♭ natural minor
B♭1C2D♭♭3E♭4F5G♭♭6A♭♭7
The major scale started from its sixth degree: same seven notes, a different centre of gravity.
The same sounds spelled from the other side are A♯ natural 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♭WA♭WB♭
What is true of it
B♭ natural minor is B♭, C, D♭, E♭, F, G♭ and A♭, and back to B♭.
Its steps are W – H – W – W – H – W – W, where W is a whole step and H a half.
On the same tonic, B♭ harmonic minor differs from it by exactly one note.
Chords made only of these notes
CdimdiminishedCm7♭5half-diminished seventhD♭majorD♭maj7major seventhE♭mminorE♭m7minor seventhFmminorFm7minor seventh
Found by testing every chord in the catalogue against these 7 sounds, not chosen.