B°7
Character: suspense
- BRtriad
- D♭3triad
- F♭5triad
- A♭𝄫7add
9 ways to play B°7
Every voicing sits inside one of the five CAGED shapes, low to high on the neck, with its octave doublings in grey.
- Triad note
- Substitute
- Added
- Anchored root
- Bass
- Doubling
Frets 1 2 0 1 0 1Notes F B D A♭Intervals ♭5 1 ♭3 𝄫7Base triadB diminished, 2nd inversion
The 𝄫7th gets a string of its own.
Frets x 11 12 10 12 xNotes A♭ D F BIntervals 𝄫7 ♭3 ♭5 1Base triadB diminished, 1st inversion
The 𝄫7th gets a string of its own.
Frets x x 3 4 3 4Notes F B D A♭Intervals ♭5 1 ♭3 𝄫7Base triadB diminished, 2nd inversion
The 𝄫7th gets a string of its own.
Frets x 2 3 1 3 xNotes B F A♭ DIntervals 1 ♭5 𝄫7 ♭3Base triadB diminished, 2nd inversion
The root drops to the string below the triad. The 𝄫7th takes the root’s string.
Frets 4 5 3 4 x xNotes A♭ D F BIntervals 𝄫7 ♭3 ♭5 1Base triadB diminished, 1st inversion
The 𝄫7th gets a string of its own.
Frets x x 6 7 6 7Notes A♭ D F BIntervals 𝄫7 ♭3 ♭5 1Base triadB diminished, 1st inversion
The 𝄫7th gets a string of its own.
Frets 7 8 9 7 9 7Notes F B D A♭Intervals ♭5 1 ♭3 𝄫7Base triadB diminished, 2nd inversion
The 𝄫7th gets a string of its own.
Frets 7 8 6 7 0 7Notes B F A♭ DIntervals 1 ♭5 𝄫7 ♭3Base triadB diminished, 2nd inversion
The root drops to the string below the triad. The 𝄫7th takes the root’s string.
Frets x x 9 10 9 10Notes B F A♭ DIntervals 1 ♭5 𝄫7 ♭3Base triadB diminished, 2nd inversion
The root drops to the string below the triad. The 𝄫7th takes the root’s string.
The construction rules B°7 follows
Start from a triad
Root, 3rd and 5th, stacked in thirds. The 3rd makes it major or minor; the 5th makes it diminished or augmented when it moves.
A third on top makes a 7th chord
A major 7th over a major triad is maj7, a ♭7 is a dominant 7. Over minor you get m7 or m(maj7); over diminished, m7♭5 or the °7, whose 7th is lowered twice.
On guitar, something has to give
Each extension takes the string of a triad note that matters less, usually the 5th, or gets a string of its own. The root and 3rd stay: they say what the chord is.
The root can move down
When an extension needs the root’s string, the root can drop to the string below the triad: an anchored voicing keeps the bass and frees a string on top.
All the rules, with examples, in the guide to the chord library.
Diminished 7th in every key
More chords on B
B°7 chord questions
What notes are in B°7?
B°7 is spelled B D F A♭: B is the root, D is the ♭3rd, F is the ♭5th, A♭ is the 𝄫7th.
What is the formula of B°7?
1 ♭3 ♭5 𝄫7. It is a B diminished triad with the 𝄫7th stacked on top.
How many ways can you play B°7 on guitar?
This page shows 9 voicings of B°7, filed under the five CAGED shapes and named by inversion, from the open position up to the 16th fret.