piano scale
F♯ altered
F♯1G♭2A♭3B♭♭4C♭5D♭6E♭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 G♭ 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
F♯HGWAHB♭WCWDWEWF♯
What is true of it
F♯ altered is F♯, G, A, B♭, C, D and E, and back to F♯.
Its steps are H – W – H – W – W – W – W, where W is a whole step and H a half.
On the same tonic, F♯ Locrian differs from it by exactly one note.
Chords made only of these notes
CmajorC7dominant seventhDmajorDaugaugmentedD7dominant seventhEdimdiminishedEm7♭5half-diminished seventhF♯dimdiminished
Found by testing every chord in the catalogue against these 7 sounds, not chosen.