Chord reference · triad

Bdim chord (B diminished)

The Bdim chord contains 3 written tones: B, D, F. Its interval formula is 1–♭3–♭5.

BDF
Quick answer: Bdim = B + D + F. Play those notes together; rearrange them to create inversions without changing the chord identity.

Bdim chord notes and interval formula

The formula 1–♭3–♭5 means the chord is measured from B using the root, minor third, and diminished fifth. In semitone numbers from the root, the pattern is 0–3–6.

DegreeIntervalSemitonesNote
1Root0B
♭3Minor Third3D
♭5Diminished Fifth6F

How to play Bdim on piano

Start with the notes in root position from low to high: B – D – F. Right hand 1–3–5; left hand 5–3–1 is a useful starting point, but black-key combinations and melodic movement may make another fingering more comfortable.

Bdim piano notes highlighted across two octaves. The darker label marks the root.

For a cleaner accompaniment, place the root in the left hand and play the remaining tones in the right. With extended chords, keep the third and seventh because they identify the chord quality most clearly.

How to play Bdim on guitar

Try the shape x-2-0-4-0-1 in standard tuning, read from low E to high E. The sounding-string details are: E mute; A fret 2: B; D open: D; G fret 4: B; B open: B; E fret 1: F. Keep every note clear and release pressure from strings marked “x.”

A playable Bdim voicing in standard E–A–D–G–B–E tuning.

This is one voicing, not the only correct shape. The chord remains Bdim whenever the essential pitch classes are present; doubling, omission, and bass-note choice change the voicing rather than the basic chord name.

Bdim inversions and slash chords

Inversions keep the same notes but place a different chord tone in the bass. They are useful for smoother bass lines, compact keyboard movement, and alternative guitar voicings.

PositionSymbolNotes low to highBass
Root positionBdimB – D – FB
1st inversionBdim/DD – F – BD
2nd inversionBdim/FF – B – DF

What Bdim sounds like and where it fits

The B diminished chord is tense and unstable. Diminished triads create strong tension. They commonly function as leading-tone or passing chords and often resolve with the root moving up by a semitone. A common voice-leading move resolves the root B upward to C.

Practice idea: play the chord, then move only one note at a time into a nearby chord. Listen for semitone resolutions and keep common tones held whenever possible.

Bdim compared with similar chords

Small interval changes create different chord names. Use this table to avoid confusing Bdim with nearby structures.

ChordQualityFormulaNotes
BmMinor1–♭3–5B, D, F♯
Bm7b5Half-Diminished Seventh1–♭3–♭5–♭7B, D, F, A
Bdim7Diminished Seventh1–♭3–♭5–♭♭7B, D, F, A♭

Frequently asked questions

What notes are in the Bdim chord?

The Bdim chord contains B, D, F. Its interval formula is 1–♭3–♭5.

How do you play Bdim on piano?

Play B, D, F together. A practical root-position fingering is right hand 1–3–5; left hand 5–3–1; adjust the fingering to your hand and musical context.

How do you play Bdim on guitar?

One compact standard-tuning shape is x-2-0-4-0-1 from the low E string to the high E string. An “x” means mute that string.

What does the symbol Bdim mean?

The root is B. The suffix dim identifies a diminished structure with the formula 1–♭3–♭5.

How many inversions does Bdim have?

A 3-note chord has 3 closed-position arrangements when every chord tone is retained: root position plus 2 inversions. Extended practical voicings may omit notes.