Four sharps - F#, C#, G#, D# (the same as E major).
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.
Four key signatures have G sharp and E sharp in them: F sharp Major, D sharp minor, C sharp Major and A sharp minor.
That would be the key of A-sharp minor, the relative to C-sharp major, which contains seven sharps. The leading tone is G-double-sharp.
D minor - more specifically, D harmonic minor (the version of the minor scale with a flat 6 and a sharp 7). However, you will never see a key signature with a B flat and a C sharp. The key signature will only contain B flat.
C# major A# minor
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.
Four key signatures have G sharp and E sharp in them: F sharp Major, D sharp minor, C sharp Major and A sharp minor.
That would be the key of A-sharp minor, the relative to C-sharp major, which contains seven sharps. The leading tone is G-double-sharp.
D minor - more specifically, D harmonic minor (the version of the minor scale with a flat 6 and a sharp 7). However, you will never see a key signature with a B flat and a C sharp. The key signature will only contain B flat.
C sharp major, or A sharp minor. The sharps are F, C, G, D, A, E and B.C# Major does
TO FIND THE KEY FROM THE KEY SIGNATUREIf the key signature has sharps:The major key is the note above the last sharp in the key signature.The minor key is the note below the last sharp in the key signature.Ex: key signature with sharps f-c-g is A major or F-sharp majorIf the key signature has flats:The major key is the note of the next to last flat in the key signature. If there is only one flat, it is F major.The minor key is the note TWO notes above the last flat in the key signature.Ex: key signature with the flats b-e-a-d-g is D-flat major or B-flat minorIf the key signature has no flats or sharps:The major key is C.The minor key is A.TO CREATE THE KEY SIGNATURE FROM THE KEYThe sharps always go in this order: F-C-G-D-A-E-B-C (circle of fifths)If you are creating the key signature for a major key, keep writing sharps until the last sharp is the note below the key you need.If you are creating the key signature for a minor key, keep writing sharps until the last sharp is the note above the key you need.Ex: The key signature for B major and G-sharp minor is f-c-g-d-a.The flats always go in this order: B-E-A-D-G-C-F (circle of fourths)If you are creating the key signature for a major key, keep writing flats until the next-to-last flat is the key you need.If you are creating the key signature for a minor key, keep writing flats until the last flat is TWO notes below the key you need.Ex: The key signature for E-flat major and C minor is b-e-a.The key signature for C major and A minor has no flats or sharps.The key signature for F major and d minor has ONE flat (B-flat).
There is no key signature that has Bb and C#.
There is not three notes in any scale or key, if you are asking about the accidentals, there is one flat (Bb) in the key signature plus an additional C sharp for the harmonic minor scale.
C# Major
G-sharp minor (generally) has five sharps, however in the melodic minor both E and F♯ need to be raised, so the key signature for G-sharp melodic minor has 5 sharps and 1 double sharp (G♯, A♯, C♯, D♯, E♯, and an Fx).