That is the signature for the key of Db. Or, it's relative minor, Bb minor.
The key signature for F major has one flat (B flat) , while the key signature for F minor has four flats (B flat, E flat, A flat, and D flat).
D major has a key signature of F sharp and C sharp D minor has a key signature of B flat
Only "B flat" is the key signature, then "C sharp" is the accidental.
B flat, E flat, A flat, D flat, G flat.
F major, or D minor. The flat is b flat.
The key signature that has B flat, A flat, E flat and D flat is Concert A flat Major.
Assuming the key signature has only one flat (B Flat) then the key is either F Major, or D minor.
The key signature for F major has one flat (B flat) , while the key signature for F minor has four flats (B flat, E flat, A flat, and D flat).
The key signature with only a B-flat is either F major or D minor.
D major has a key signature of F sharp and C sharp D minor has a key signature of B flat
The key of D-flat has 5 flats: B, E, A, D and G.
B flat, E flat, A flat, D flat
The key signature of the F flat major key has six flats: B flat, E flat, A flat, D flat, G flat, and C flat.
Only "B flat" is the key signature, then "C sharp" is the accidental.
B flat, E flat, A flat, D flat, G flat.
F major, or D minor. The flat is b flat.
B flat, E flat, A flat, D flat, G flat, C flat, F flat. It's the opposite order to that of the sharps in a key signature.