|Relative key||C♯ major
enharmonic: D♭ major
|Parallel key||A♯ major
enharmonic: B♭ major
|A♯, B♯, C♯, D♯, E♯, F♯, G♯, A♯|
A-sharp minor or A♯ minor is a minor scale based on A-sharp. The A♯ minor scale has pitches A♯, B♯, C♯, D♯, E♯, F♯, and G♯. For the harmonic minor scale, G is used instead of G♯. Its key signature has seven sharps (see below: Scales and keys).
Its relative major is C-sharp major. Its parallel major is A-sharp major. This is usually replaced by B-flat major, since A-sharp major has 4 sharps and 3 double sharps. Exceptions include Chopin's Polonaise-Fantaisie in A-flat major, Op. 61, which has a brief passage of about 6 bars actually notated in A-sharp major, inserting the necessary double-sharps as accidentals. The overall harmonic context is an extended theme in B major, which briefly modulates to A-sharp major.
The direct enharmonic equivalent of A-sharp minor is B-flat minor.
Changes needed for the melodic and harmonic versions of the scale are written in with accidentals as necessary.
The enharmonic equivalent B-flat minor is often used in most musical compositions instead of A-sharp minor, thus indicating that A-sharp minor is not a practical key for compositions and is one of the least used minor keys in music. However, there were some composers in previous centuries that have composed music in this key, such as Christian Heinrich Rinck (Prelude No. 16 from Op. 55/1, and Exercise No. 16 from Op. 67).
Scales and keys 
|Diatonic scales and keys|
|The table indicates the number of sharps or flats in each scale. Minor scales are written in lower case.|
This day aria was written in this key