piano scale
A♯ diminished (whole–half)
Eight notes alternating whole step and half step. Symmetrical, so it repeats every minor third.
The same sounds spelled from the other side are B♭ diminished (whole–half).
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
What is true of it
A♯ diminished (whole–half) is A♯, B♯, C♯, D♯, E, F♯, F𝄪 and G𝄪, and back to A♯.
Its steps are W – H – W – H – W – H – W – H, where W is a whole step and H a half.
Written correctly it needs 9 alterations, F𝄪 and G𝄪 among them. That is what the letters force, and it is also why nobody writes music in this key: the same notes spelled from the other side are easier to read.
Chords made only of these notes
Found by testing every chord in the catalogue against these 8 sounds, not chosen.
Other scales on A♯
C dim W-HC♯ dim W-HD♭ dim W-HD dim W-HD♯ dim W-HE♭ dim W-HE dim W-HF dim W-Hall 374