piano scale
A♯ natural minor
A♯1B♯2C♯♭3D♯4E♯5F♯♭6G♯♭7
The major scale started from its sixth degree: same seven notes, a different centre of gravity.
The same sounds spelled from the other side are B♭ natural minor.
Written out
Every accidental is written in, rather than left to a key signature, so the letters can be read one at a time.
The step pattern
A♯WB♯HC♯WD♯WE♯HF♯WG♯WA♯
What is true of it
A♯ natural minor is A♯, B♯, C♯, D♯, E♯, F♯ and G♯, and back to A♯.
Its steps are W – H – W – W – H – W – W, where W is a whole step and H a half.
It costs 7 alterations to write — near the limit of what a key signature can carry.
On the same tonic, A♯ harmonic minor differs from it by exactly one note.
Chords made only of these notes
C♯majorC♯maj7major seventhD♯mminorD♯m7minor seventhF♯majorF♯maj7major seventhG♯majorG♯7dominant seventh
Found by testing every chord in the catalogue against these 7 sounds, not chosen.