No key signatures contain only those three sharps. With the A-sharp, it could be the keys of B major, F-sharp major, or C-sharp major (or any of their relative minor keys).
The key with three sharps is A major, however A major uses C sharp - alongside with G sharp and F sharp - instead of D sharp.
Four key signatures have G sharp and E sharp in them: F sharp Major, D sharp minor, C sharp Major and A sharp minor.
Key of F#, key of B, key of E, key of A, key of D, and key of G
B Major is the 1st major scale that CONTAINS A sharp and F sharp within its key signature but has a total of 5 sharps which are, F# C# G# D# A# F# Major also CONTAINS A sharp and F sharp within its key signature but has a total of 6 sharps which are, F# C# G# D# A# E# C# Major also CONTAINS A sharp and F sharp within its key signature but has a total of 7 sharps which are, F# C# G# D# A# E# B#
G sharp
The key with three sharps is A major, however A major uses C sharp - alongside with G sharp and F sharp - instead of D sharp.
The key signature for D sharp minor would be the one for F sharp major: FCGDAE. You can also think of it as E flat minorwhich is related to g flat major in which the key signature would be BEADGC.
Four key signatures have G sharp and E sharp in them: F sharp Major, D sharp minor, C sharp Major and A sharp minor.
Key of F#, key of B, key of E, key of A, key of D, and key of G
B Major is the 1st major scale that CONTAINS A sharp and F sharp within its key signature but has a total of 5 sharps which are, F# C# G# D# A# F# Major also CONTAINS A sharp and F sharp within its key signature but has a total of 6 sharps which are, F# C# G# D# A# E# C# Major also CONTAINS A sharp and F sharp within its key signature but has a total of 7 sharps which are, F# C# G# D# A# E# B#
G sharp
G sharp
There is only one sharp that a G major has in its key signature.
C# Major
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).
C sharp major, or A sharp minor. The sharps are F, C, G, D, A, E and B.C# Major does
B major, or G sharp minor. The sharps are F, C, G, D and A. F#, C#, G#, D#, A#