Bdim13(#9) Diminished
The Bdim13(#9) chord is built from the notes B – D – F – Ab – C## – G#.
Piano sound loads on first tap.
Chord tones, one by one
BRoot
Root
The fundamental note the chord is built on — B.
DThird
Minor third
Three semitones — makes the chord minor (darker, sadder).
FFifth
Diminished fifth (♭5)
Six semitones — a flat fifth. Creates instability, typical of m7♭5 and diminished chords.
AbSeventh
Diminished seventh (♭♭7)
Nine semitones — a doubly-flat seventh, found in fully diminished 7th chords.
C##Extension
Sharp ninth (♯9)
A ♯9 — the gritty 'Hendrix' tension over a dominant chord.
G#Extension
Thirteenth (13)
A 13th — full, rich top extension.
🎼 Related scales
🎹 Modal analysis
This chord implies the Whole-half diminished scale.
🎸 Genres
Bebop jazz · Hard bop · Gypsy jazz