key signature
B♭ minor
B♭1C2D♭3E♭4F5G♭6A♭7
5 flats, written B♭ E♭ A♭ D♭ G♭
The chords that live in it
B♭mdegree 1 · minorCdimdegree 2 · diminishedD♭degree 3 · majorE♭mdegree 4 · minorFmdegree 5 · minorG♭degree 6 · majorA♭degree 7 · major
Built by stacking thirds inside the scale and asking what quality comes out, rather than from a table of roman numerals.
What is true of it
B♭ minor has 5 flats.
They are written in this order, always: B♭ E♭ A♭ D♭ G♭.
Its notes are B♭, C, D♭, E♭, F, G♭ and A♭.
Relative: D♭ major has the same 5 flats. Parallel: B♭ major has 2 flats, which is why changing mode changes the signature by three.
Every key
C♭ majorG♭ majorD♭ majorA♭ majorE♭ majorB♭ majorF majorC majorG majorD majorA majorE majorB majorF♯ majorC♯ majorA♭ minorE♭ minorF minorC minorG minorD minorA minorE minorB minorF♯ minorC♯ minorG♯ minorD♯ minorA♯ minor