B 7th flat 5 chord on guitar (B7♭5)

Also called or written B7♭5, B, B Dominant 7th Flat 5 or B 7th ♭5

B 7th flat 5 is built from B, D♯, F, and A. The open voicing spreads the fingers across four frets, making it a demanding stretch for the left hand.

BD♯ABFEADGBE
Positions on the neck1 of 5
Practice B 7th flat 5 chord

How it is built

BRootD♯Major thirdFDiminished fifthAMinor seventh

Formula 1, 3, ♭5, ♭7

Inversions
  • Root positionB–D♯–F–AB7♭5×-2-1-2-0-1
  • First inversionD♯–F–A–BB7♭5/D♯×-×-1-2-0-1
  • Second inversionF–A–B–D♯B7♭5/F1-0-1-2-0-1
  • Third inversionA–B–D♯–FB7♭5/A×-0-1-2-0-1

How do you play a B 7th flat 5 chord on guitar?

B 7th flat 5 is played in open position as × 2 1 2 0 1: ring finger on the A string at fret 2, index finger on the D string at fret 1, pinky finger on the G string at fret 2 and middle finger on the high e string at fret 1. The B string rings open. The low E string stays muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)23B (1)
4 (D)11D♯ (3)
3 (G)24A (♭7)
2 (B)openB (1)
1 (e)12F (♭5)

AdvancedThe open voicing requires a wide stretch from the 1st fret on the D string to the 2nd fret on the G string with the pinky.

2nd fret

B 7th flat 5 is played at the 2nd fret as × 2 3 2 4 ×: index finger on the A string at fret 2, ring finger on the D string at fret 3, middle finger on the G string at fret 2 and pinky finger on the B string at fret 4. The low E and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)21B (1)
4 (D)33F (♭5)
3 (G)22A (♭7)
2 (B)44D♯ (3)
1 (e)muted

6th fret

B 7th flat 5 is played at the 6th fret as 7 6 7 8 6 ×: barre your index finger across fret 6, middle finger on the low E string at fret 7, ring finger on the D string at fret 7 and pinky finger on the G string at fret 8. The high e string stays muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)72B (1)
5 (A)61 (barre)D♯ (3)
4 (D)73A (♭7)
3 (G)84D♯ (3)
2 (B)61 (barre)F (♭5)
1 (e)muted

7th fret

B 7th flat 5 is played at the 7th fret as 7 8 7 8 × ×: index finger on the low E string at fret 7, ring finger on the A string at fret 8, middle finger on the D string at fret 7 and pinky finger on the G string at fret 8. The B and high e strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)71B (1)
5 (A)83F (♭5)
4 (D)72A (♭7)
3 (G)84D♯ (3)
2 (B)muted
1 (e)muted

9th fret

B 7th flat 5 is played at the 9th fret as × × 9 10 10 11: index finger on the D string at fret 9, middle finger on the G string at fret 10, ring finger on the B string at fret 10 and pinky finger on the high e string at fret 11. The low E and A strings stay muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)muted
4 (D)91B (1)
3 (G)102F (♭5)
2 (B)103A (♭7)
1 (e)114D♯ (3)

Why it sounds like that

B 7th flat 5 combines a major 3rd, a diminished 5th, and a minor 7th. The diminished 5th between B and F creates the chord's signature tension. Compare it to B 7th, which uses F♯ instead of F.

What goes wrong with B 7th flat 5?

  • Letting the low E string ring out and clash with the chord.
  • Flattening the pinky and muting the B string.
  • Not pressing the D string hard enough, causing a buzz at the 1st fret.

When to use it

B 7th flat 5 functions as a dominant chord in keys like E major, resolving to E major. Its dissonance suits jazz and experimental rock. Use it before E major or B 7th.

Changing to and from B 7th flat 5

  • From the open voicing, move your index finger to the 2nd fret of the A string and your ring finger to the 3rd fret of the D string for C 7th flat 5.
  • Slide the 2nd-fret shape up one fret to the 3rd fret to get C 7th flat 5.

Which voicing to use

The open voicing is the only option without a barre, but the 6th-fret barre version offers a more compact shape. The 9th-fret voicing places the root on the D string for a higher register.

Other B chords

Common questions

Why is the low E string muted in B 7th flat 5?

The open E string is not a chord tone in B 7th flat 5. Muting it keeps the voicing clean and prevents an unwanted note from ringing.

What is the difference between B 7th flat 5 and B 7th?

B 7th flat 5 lowers the perfect 5th of B 7th by one semitone to F. That creates a diminished 5th interval and a more dissonant sound.

How does B 7th flat 5 resolve?

B 7th flat 5 typically resolves to E major. The tritone between B and F pulls strongly toward the E major chord.