piano scale
B♭ Phrygian dominant
B♭1C♭♭2D3E♭4F5G♭♭6A♭♭7
The fifth mode of harmonic minor: a flat second over a major third, so the step from the second to the third is a step and a half.
The same sounds spelled from the other side are A♯ Phrygian dominant.
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
B♭HC♭W+HDHE♭WFHG♭WA♭WB♭
What is true of it
B♭ Phrygian dominant is B♭, C♭, D, E♭, F, G♭ and A♭, and back to B♭.
Its steps are H – W+H – H – W – H – W – W, where W is a whole step and H a half.
On the same tonic, B♭ Phrygian differs from it by exactly one note.
Chords made only of these notes
DdimdiminishedDaugaugmentedE♭mminorFdimdiminishedFm7♭5half-diminished seventhG♭augaugmentedA♭mminorA♭dimdiminished
Found by testing every chord in the catalogue against these 7 sounds, not chosen.
Other scales on B♭
B♭ Lydian dominantexoticB♭ alteredexoticB♭ double harmonicexoticB♭ majormajorB♭ natural minorminorB♭ harmonic minorminor
C phr domC♯ phr domD♭ phr domD phr domD♯ phr domE♭ phr domE phr domF phr domall 374