Bbm11b5 Half-Diminished
The Bbm11b5 chord is built from the notes Bb – Db – Fb – Ab – C – Eb.
Piano sound loads on first tap.
Chord tones, one by one
BbRoot
Root
The fundamental note the chord is built on — Bb.
DbThird
Minor third
Three semitones — makes the chord minor (darker, sadder).
FbFifth
Diminished fifth (♭5)
Six semitones — a flat fifth. Creates instability, typical of m7♭5 and diminished chords.
AbSeventh
Minor seventh (♭7)
Ten semitones — the dominant/minor seventh. Adds bluesy tension (7, m7).
CExtension
Ninth (9)
A 9th — colorful extension a whole step above the octave.
EbExtension
Eleventh (11)
An 11th — a suspended, airy color on top of the chord.
🎼 Related scales
Locrian ♮2 (half-diminished)melodic minor a major 6th below
🎹 Modal analysis
This chord implies the Locrian ♮2 (half-diminished) scale; its characteristic note is the natural 2nd, softer than plain Locrian. It is a mode of the melodic minor a major 6th below.
🎸 Genres
Modern jazz · Post-bop · Fusion