B Super-Locrian 𝄫7 Scale
B Super-Locrian 𝄫7 contains 7 notes: B, C, D, E♭, F, G, A♭. It has 2 flats: E♭, A♭. The step pattern is H–W–H–W–W–H–W+H. It is derived from B Harmonic Minor.
Super-Locrian bb7 (Ultralocrian) is the most dissonant mode of harmonic minor. It's an extreme, unstable sound used to create moments of maximum harmonic tension.
Built as 1 - b2 - b3 - b4 - b5 - b6 - bb7, this is the 7th mode of harmonic minor and the only mode in this family that naturally generates a fully diminished 7th chord (dim7). The b4 (enharmonic major 3rd) and bb7 make it extremely chromatic. It is almost entirely theoretical in isolation.
You can technically play this over any dim7 chord, but the b4 clashes heavily with the underlying harmony. Use it sparingly as a passing diminished sound resolving up a half step to a minor chord. Best treated as a brief chromatic color rather than a sustained tonality.