|Relative key||D♭ major|
|Parallel key||B♭ major|
|Dominant key||F minor|
enharmonic: D♯ minor
|B♭, C, D♭, E♭, F, G♭, A♭|
B♭ minor is a minor scale based on B♭, consisting of the pitches B♭, C, D♭, E♭, F, G♭, and A♭. Its key signature has five flats. Its relative major is D♭ major and its parallel major is B♭ major. Its enharmonic equivalent, A♯ minor, which would contain seven sharps, is not normally used.
The B♭ natural minor scale is:
B♭ minor is traditionally a 'dark' key. Important oboe solos in this key in the orchestral literature include the second movement of Tchaikovsky's Symphony No. 4, which depicts "the feeling that you get when you are all alone" in Tchaikovsky's words. Tchaikovsky's Piano Concerto No. 1 is also in B♭ minor. An Alpine Symphony by Richard Strauss begins and ends in B♭ minor.
The old valveless horn was barely capable of playing in B♭ minor; the only example found in 18th-century music is a modulation that occurs in the first minuet of Franz Krommer's Concertino in D major, Op. 80.