There is no such key.
The key of B flat on the piano has two flats (Bb and Eb).
The G flat key is the black key left to G and right to F on the keyboard.
The key signature with only a B-flat is either F major or D minor.
The middle black key in the set of three black keys
E-flat major.
B-flat
Notice that the black keys of a piano are grouped into two's and three's. The middle key of any group of three black keys is A flat. You would play that key and that note just as you would any other key on the keyboard.
Yes, A flat is the same black key as G sharp on the piano. It is the middle black key in the three black key groups.
Piano plays in c.. To transpose to Eb lower the written note one line or space and use the key signature of b and e flat and add the written key signature
If you are talking about key signatures Bb major has 2bs but Bb minor has 5bs.
F# minor, which has 3 sharps in the key signature.
A flat key is a key that has a flat on its tonic note. A sharp key is a key that has a sharp on its tonic note.