Chord · 7ths

Bdim7 — B Diminished 7th

Bdim7 is the B diminished 7th chord. It is built on the root B with minor 3rd (D), diminished 5th (F) and diminished 7th (A♭) above it — the formula 1 ♭3 ♭5 𝄫7, sounding the notes B D F A♭. On the piano it sits at B (octave 3) and above in the library's voicing; the same 4 notes in any octave are still Bdim7.

Root
B
Quality
Diminished 7th
Formula
1 ♭3 ♭5 𝄫7
Notes
B D F A♭

On the keyboard

Bdim7 on the piano keyboard: B D F A♭1235BDFA♭

Right-hand fingering for this voicing: 1–2–3–5 (1 is the thumb).

The notes of Bdim7

DegreeNoteInterval from the rootPitch
1BrootB3
♭3Dminor 3rdD4
♭5Fdiminished 5thF4
𝄫7A♭diminished 7thA♭4

Other 7ths on B

Diminished 7th chords on every root

Part of the chord reference. See also the scales and the keys.