B Diminished Seventh Chord

Chord Tones: B Diminished Seventh Chord

Symbol: dim7, °7 — Formula: 1-♭3-♭5-𝄫7

DegreeNoteFrequency (A=440, Equal)
1 B4 493.883 Hz
♭3 D4 293.665 Hz
♭5 F4 349.228 Hz
𝄫7 G♯4 415.305 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolBdim7
All Common Symbolsdim7, °7
Interval Formula1-♭3-♭5-𝄫7
Harmonic Categorytense

Roman numeral (e.g. I, IV, V) and Nashville Number notation are key-dependent. See Keys pages for chord function within specific keys.

Inversions

InversionNotes (low to high)Bass NoteSlash Notation
Root Position B4 D4 F4 G♯4 B B Diminished Seventh Chord
First Inversion D4 F4 G♯4 B4 D B Diminished Seventh Chord/D
Second Inversion F4 G♯4 B4 D4 F B Diminished Seventh Chord/F
Third Inversion G♯4 B4 D4 F4 G♯ B Diminished Seventh Chord/G♯

Harmonic Function

The B diminished seventh chord commonly functions as the leading tone (vii) in C major or dominant (V) in E major. Its harmonic role varies by key — in major keys it provides extended harmonic tension.

The diminished seventh chord consists of four equally-spaced minor thirds, creating a symmetrical, highly dissonant chord. It is used as a dramatic pivot chord and in chromatic passing harmony. The B Diminished Seventh Chord specifically contains 4 notes: B, D, F, G♯ (formula: 1-♭3-♭5-𝄫7). On guitar, B-rooted chords are typically played as barre chords at the second or seventh fret, and on piano they use a comfortable mix of black and white keys. K-pop, J-pop, and modern R&B productions frequently feature B-rooted chords, chosen for how the key sits within typical vocal ranges.

Common Progressions

The B Diminished Seventh Chord frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

Songs Featuring the Diminished Seventh Chord

Well-known songs where the B Diminished Seventh Chord — or this chord type — plays a prominent role:

Tuning Frequencies Across Temperaments

Frequencies shown at A=440 Hz. View full temperament data for any note.

NoteEqual Temp.PythagoreanJust Intonation
B4 493.883 Hz 495.000 Hz 490.548 Hz
D4 293.665 Hz 293.332 Hz 294.329 Hz
F4 349.228 Hz 347.654 Hz 348.834 Hz
G♯4 415.305 Hz 417.657 Hz 418.601 Hz

Scales Containing the B Diminished Seventh Chord

These scales include the B Diminished Seventh Chord as a diatonic or characteristic chord: