piano scale
A♯ altered
A♯1B♭2C♯♭3D♭4E♭5F♯♭6G♯♭7
The seventh mode of melodic minor. Every degree above the tonic that can be altered, is.
The same sounds spelled from the other side are B♭ altered.
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♯HBWC♯HDWEWF♯WG♯WA♯
What is true of it
A♯ altered is A♯, B, C♯, D, E, F♯ and G♯, and back to A♯.
Its steps are H – W – H – W – W – W – W, where W is a whole step and H a half.
On the same tonic, A♯ Locrian differs from it by exactly one note.
Chords made only of these notes
C♯mminorC♯m7minor seventhDaugaugmentedEmajorE7dominant seventhF♯majorF♯augaugmentedF♯7dominant seventh
Found by testing every chord in the catalogue against these 7 sounds, not chosen.