The Bb diminished whole–half / A# diminished whole–half scale has 8 notes: Bb, C, Db, Eb, E, F#, G and A. Its formula is 1 2 b3 4 b5 #5 6 7 and its steps, in tones, are 1 – ½ – 1 – ½ – 1 – ½ – 1 – ½.
The whole–half diminished scale alternates a tone and a semitone: eight symmetrical notes, used in jazz over diminished chords.
Bb diminished whole–half
Bb C Db Eb E F# G A · 1 2 b3 4 b5 #5 6 7
Colored dots: notes of the scale, the root is the darkest.