ArpeggiosEN

Arpeggio

B♭ m7♭5

Augmented / Diminished

Formula
1 ♭3 ♭5 ♭7
Notes
B♭ D♭ F♭ A♭

Notation

441♭3♭5♭7

Fretboard — frets 0–24

B♭ m7♭5 — frets 0 to 24, 50 notes, roots in orange♭5♭71♭3♭5♭71♭3♭5♭3♭5♭71♭3♭5♭71♭71♭3♭5♭71♭3♭5♭5♭71♭3♭5♭71♭31♭3♭5♭71♭3♭5♭7♭5♭71♭3♭5♭71♭3♭50123456789101112131415161718192021222324
B♭ m7♭5 — frets 0 to 24, 50 notes, roots in orange♭5♭71♭3♭5♭71♭3♭5♭3♭5♭71♭3♭5♭71♭71♭3♭5♭71♭3♭5♭5♭71♭3♭5♭71♭31♭3♭5♭71♭3♭5♭7♭5♭71♭3♭5♭71♭3♭50123456789101112131415161718192021222324

Degrees

DegreeNoteIntervalSemitonesRole
1B♭perfect unison0The root — the tonal centre every other note is heard against; land on it and the sound resolves.
♭3D♭minor third3The minor third — the dark counterpart of the major third; it turns a shape minor and colours m, m7 and the minor scales.
♭5F♭diminished fifth6The diminished fifth — a flattened fifth that destabilises the chord; dim, m7♭5 and locrian are built on it.
♭7A♭minor seventh10The minor seventh — the dominant's engine; a whole step under the root, it turns a triad into a 7 chord and drives the resolution.

About this arpeggio

The minor seventh flat five — the half-diminished chord — is the softer, more musical cousin of the diminished seventh. It keeps the minor third and flat fifth but takes a plain minor seventh, which makes it sound melancholic rather than menacing. In a minor key it is the ii chord of the ii–V–i cadence, the natural home of the locrian scale, and a gateway into altered dominant sounds. Jazz players also use it as a substitute for a dominant flat-nine. Arpeggiated, it maps perfectly onto the locrian shape. Listen for the minor seventh relaxing the flat fifth's bite.

How to practise this arpeggio

  • Play it as the ii chord of a minor ii–V–i and feel the pull.
  • Compare it with dim7 and hear the softer, more melancholic seventh.
  • Resolve the flat fifth down to the root of the next chord.
  • Loop it over a half-diminished vamp and accent the seventh.