The B diminished seventh chord, often written as Bdim7, is a four-note chord consisting of B (root), D (minor third), F (diminished fifth), and A♭ (diminished seventh). This chord is constructed by stacking three consecutive minor thirds, which gives it a highly tense and unstable sound that naturally demands resolution. The B diminished seventh chord is commonly used in classical, jazz, and contemporary music to create dramatic tension, facilitate smooth modulation between keys, or act as a passing chord that leads to a more stable harmony. Its symmetrical structure and dissonant intervals provide a dark, suspenseful character, making it a powerful tool for adding emotional intensity and harmonic complexity to musical compositions.
Name: B diminished seventh chord
Symnonyms:: B fully diminished chord
Notes: B, D, F, A♭
Intervals: 1, ♭3, ♭5, 𝄫7
Chord symbol: Bo7
Alternative symbols: Bdim7, Bdim, Bo
Type: Tetrad (four-note chord)
B diminished seventh chord on the Staff
B diminished seventh chord on Piano
B diminished seventh chord on Guitar
B diminished seventh chord on Ukulele
Rowan Ellis is a musician and educator with a passion for exploring the language of harmony and melody. With years of experience across classical, jazz, and contemporary styles, Rowan breaks down music theory into clear, practical insights. His goal is to make chords and scales less intimidating and more inspiring for every musician.