The One ThingPractising the Theory for Progressive and Jazz Guitarists

The key of B♭ minor

B♭ C D♭ E♭ F G♭ A♭

5 flats: B♭ E♭ A♭ D♭ G♭. Relative major: The key of D♭ major.

The triads of the key

i
B♭m

ii°
C°

III
D♭

iv
E♭m

v
Fm

VI
G♭

VII
A♭

i7
B♭m7

iiø7
Cm7♭5

IIImaj7
D♭maj7

iv7
E♭m7

v7
Fm7

VImaj7
G♭maj7

VII7
A♭7

In practice the V of a minor key is almost always major, taken from the harmonic minor: F7 (V7), which carries the leading tone A.