C Sharp Major has 6 key signatures which are all sharps:
There is also another major key that has 7 sharp keys.
The D minor key has a B-flat in it's key signature, but the D harmonic minor raises the seventh note from C to C-sharp both ascending and descending, so the D harmonic minor scale is the musical scale with both a B-flat and a C-sharp.
The melodic minor uses a raised 6th and 7th on the way up. The term "sharpen" means to raise a given natural (white) note from it's normal pitch so it is generally incorrect to use this term when referring to degrees in a scale - since we sometimes need to use a natural sign (if the note is already flat by the key signature) or a double sharp (if the note is already sharp by the key signature) when raising the note.
Makes no sense ... B sharp IS C. To play C natural, C sharp, D, E, F sharp doesn't make any musical sense.
The scale with 4 flats is ......
A-flat major!!!!!!!
F sharp Major, or D sharp minor. The sharps are F, C, G, D, A and E.
B-major: F#, C#, G#, D#, A#
A Major has three sharps: F, C, and G.
F# major.
There are no sharps or flats in C Major.
The C major scale...
A major has 3 sharps, A minor has no sharps or flats.
There are no flats or sharps. Its relative major scale is C major, which has all of the same notes.
E Major
The three sharps in A major are F, C, and G.
The major scale with 2 sharps is D major, they are F and C sharp.
There are no sharps or flats in C Major.
C major has no sharps or flats.
A major
The major scale with five sharps is B major. The five sharps, in written order, according to the key signature, are F#, C#, G#, D#, A#.
The B major scale has 5 sharps: F#, C#, G#, D#, A#.
The D major scale has F# and C#.
C major and A minor both have no sharps or flats.
The C major scale...
C major scale and A minor.
Concert A Major