B diminished chord on guitar (Bdim)

Also called or written Bdim or

B diminished contains the notes B, D, and F. The 2nd fret shape is compact but requires muting both E strings.

2frBFBDEADGBE
Positions on the neck1 of 5
Practice B diminished chord

How it is built

BRootDMinor thirdFDiminished fifth

Formula 1, ♭3, ♭5

Inversions

How do you play a B diminished chord on guitar?

B diminished is played at the 2nd fret as × 2 3 4 3 ×: index finger on the A string at fret 2, middle finger on the D string at fret 3, pinky finger on the G string at fret 4 and ring finger on the B string at fret 3. The low E and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)21B (1)
4 (D)32F (♭5)
3 (G)44B (1)
2 (B)33D (♭3)
1 (e)muted

IntermediateThe 2nd fret shape demands a four-fret stretch and precise muting of both E strings, making it intermediate.

7th fret

B diminished is played at the 7th fret as 7 8 9 7 × ×: index finger on the low E string at fret 7, ring finger on the A string at fret 8, pinky finger on the D string at fret 9 and middle finger on the G string at fret 7. The B and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)71B (1)
5 (A)83F (♭5)
4 (D)94B (1)
3 (G)72D (♭3)
2 (B)muted
1 (e)muted

Bdim/D inversion · fret 3

B diminished is played at the 3rd fret as × 5 3 4 3 ×: pinky finger on the A string at fret 5, index finger on the D string at fret 3, ring finger on the G string at fret 4 and middle finger on the B string at fret 3. The low E and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)54D (♭3)
4 (D)31F (♭5)
3 (G)43B (1)
2 (B)32D (♭3)
1 (e)muted

Bdim/D inversion · fret 8

B diminished is played at the 8th fret as 10 8 9 10 × ×: ring finger on the low E string at fret 10, index finger on the A string at fret 8, middle finger on the D string at fret 9 and pinky finger on the G string at fret 10. The B and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)103D (♭3)
5 (A)81F (♭5)
4 (D)92B (1)
3 (G)104F (♭5)
2 (B)muted
1 (e)muted

Bdim/D inversion · fret 10

B diminished is played at the 10th fret as × × 12 10 12 10: ring finger on the D string at fret 12, index finger on the G string at fret 10, pinky finger on the B string at fret 12 and middle finger on the high e string at fret 10. The low E and A strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)muted
4 (D)123D (♭3)
3 (G)101F (♭5)
2 (B)124B (1)
1 (e)102D (♭3)

Why it sounds like that

B diminished is built from the formula 1, ♭3, ♭5, giving B, D, and F. The flattened fifth creates the chord's unstable quality. Compare it to B minor, which raises the fifth to F♯.

What goes wrong with B diminished?

  • Letting the low E string ring out, adding an E that is not part of B diminished.
  • Flattening the pinky on the G string, causing the 4th fret note to buzz.
  • Strumming the high E string, which introduces an outside note.

When to use it

B diminished functions as the vii° chord in C major, leading to C major. It also works as a passing chord between B minor and C major. Use it in rock or jazz for a tense, unresolved color.

Changing to and from B diminished

  • Slide the 2nd fret shape up one fret to the 3rd fret to get C diminished.
  • Move to B minor by lifting the pinky from the G string's 4th fret and playing the 4th fret on the B string instead.

Which voicing to use

The 2nd fret shape is the most common and keeps the root B in the bass. The 7th fret shape repeats the voicing higher. The Bdim/D inversions place D in the bass, softening the root emphasis.

Other B chords

Common questions

What is the difference between B diminished and B minor?

B diminished has a flattened fifth (F), while B minor has a perfect fifth (F♯). The diminished fifth creates a more dissonant, unstable sound.

Can I play B diminished as a barre chord?

The 2nd fret shape uses no barre, but the 7th fret shape is movable. Slide the 7th fret shape down one fret to get B♭ diminished.

Why are both E strings muted in the 2nd fret shape?

The open E strings are not chord tones of B diminished. Muting them keeps the voicing clean and prevents an unwanted major second clash.

How is B diminished written?

B diminished is written as B° or Bdim. The root is B, and the symbols are B° and Bdim.