B Half Whole Diminished, Mapped for the Bass

B Half Whole Diminished runs 8 notes to the octave, laid across this seat's EADG fretboard with every B marked. A blues phrase is short and keeps coming home to one pitch; the marked notes are where it comes home to.

Tense, symmetrical, and slightly sinister — alternating half and whole steps pack in the b9, #9, #11, and 13, so it sounds like a dominant chord stretched to breaking point. Edgy, jazzy, and restless.

Heard in: Jazz lines over 13b9 dominant chords, fusion, film-noir and horror scoring — the sound of a V chord that refuses to settle.

On the bass a scale supplies the notes between one chord and the next — the steps a line takes on its way to the change — far more often than it is played as a run.

Whatever scale you start from, the blues bends it: the third and the seventh get pushed flat, or somewhere between flat and natural, and that pull against the chord underneath is most of what the idiom sounds like.