As the ii in a minor ii-V-iA♭ minor
The minor cadence. B♭m7♭5 leads into the dominant, and the seventh is what makes it a ii rather than a diminished triad.
B♭m7♭5 Chord: Guitar, Piano and Notes
The B♭m7♭5 chord is a half-diminished chord built on the root note B♭. Its notes are B♭, D♭, F♭ and A♭. It's enharmonically the same chord as A♯m7♭5.
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Short answer
Half-diminished chords (m7♭5) sit between a diminished triad and a minor seventh. They're the signature ii chord in minor keys and show up constantly in jazz standards and moody ballads.
- Notes
- B♭ · D♭ · F♭ · A♭
- Formula
- 1 · ♭3 · ♭5 · ♭7
- Semitones
- 0 · 3 · 6 · 10
- Note
- B♭
- Quality
- Half-Diminished (m7♭5)
- Symbol
- B♭m7♭5
B♭m7♭5 on piano
4 notesView:
Switch to the interactive diagram to hear the chord, change voicing and swap finger numbers for note names.
To play B♭m7♭5 on piano, place your right hand with your thumb on B♭, index finger on D♭, middle finger on F♭ and little finger on A♭. Press the keys together and listen for an even sound. On the keyboard B♭, D♭ and A♭ are black keys and F♭ is white, the key you'd normally call E. The thumb starts on a black key, so slide the whole hand a little further in, towards the fallboard. Practice moving in and out of the chord slowly, then bring in a metronome.
- B♭1
- D♭♭3
- F♭♭5
- A♭♭7
B♭m7♭5 on guitar
View:
Switch to the interactive diagram to hear the chord, change voicing and swap finger numbers for note names.
On guitar, B♭m7♭5 is commonly played with the voicing shown above. This one is a barre at fret 6: keep the index finger flat across the strings and curve the others so they don't mute the strings next to them. Don't play strings 2 and 1.
B♭ · D♭ · F♭ · A♭
Play B♭m7♭5 on the online piano
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B♭m7♭5 chord notes
Also known as A♯m7♭5
| Degree | Interval | Semitones | Note | Hear |
|---|---|---|---|---|
| 1 | Root | 0 | B♭(Bb) | |
| ♭3 | Minor third | 3 | D♭(Db) | |
| ♭5 | Diminished fifth | 6 | F♭(Fb) | |
| ♭7 | Minor seventh | 10 | A♭(Ab) |
How to use the B♭m7♭5 chord
The B♭m7♭5 chord is built from a root, a minor third, a diminished fifth and a minor seventh. Start at the root B♭ and stack the intervals to get the whole chord: B♭, D♭, F♭ and A♭. The same formula gives you the chord in any other key.
Half-diminished chords are most common in jazz standards. They frequently act as the iiø of a minor ii-V-i, leading into the dominant that resolves to a minor tonic.
In major keys B♭m7♭5 is the viiø7 in C♭ major; in minor keys it's the iiø7 in A♭ minor.
How B♭m7♭5 differs from similar chords
B♭m7♭5 differs from B♭m7 by one lowered note, the fifth, and from B♭°7 by one raised note, the seventh. That in-between position is where the name half-diminished comes from. In a minor key it is the ii chord, so it almost always leads to a dominant seventh.
Where B♭m7♭5 is used
A half-diminished seventh has one main use: it is the ii of a minor key, leading into the dominant. A major key builds the same chord on its seventh degree.
As the leading-tone chordC♭ major
- viiø7B♭m7♭5
- Imaj7C♭maj7
The chord a major key builds on its seventh degree, resolving up a semitone onto the tonic.
Questions people ask
- What notes are in the B♭m7♭5 chord?
- The B♭m7♭5 chord contains B♭, D♭, F♭ and A♭ (Bb, Db, Fb and Ab in plain text).
- Is the B♭m7♭5 chord major or minor?
- B♭m7♭5 is a half-diminished chord. Half-diminished chords (m7♭5) sit between a diminished triad and a minor seventh. They're the signature ii chord in minor keys and show up constantly in jazz standards and moody ballads.
- What key is the B♭m7♭5 chord in?
- In major keys B♭m7♭5 is the viiø7 in C♭ major; in minor keys it's the iiø7 in A♭ minor.
- How do you play B♭m7♭5 on piano?
- Place your fingers on B♭, D♭, F♭ and A♭ and play them together. The root usually goes to the little finger of the left hand, the upper notes to the right. On the keyboard B♭, D♭ and A♭ are black keys and F♭ is white, the key you'd normally call E. The thumb starts on a black key, so slide the whole hand a little further in, towards the fallboard.
- How do you play B♭m7♭5 on guitar?
- Use the fingering in the diagram above. This one is a barre at fret 6: keep the index finger flat across the strings and curve the others so they don't mute the strings next to them. Don't play strings 2 and 1.
- What is another name for the B♭m7♭5 chord?
- B♭m7♭5 is enharmonically equivalent to A♯m7♭5. Both chord names describe exactly the same notes, but the spelling depends on the key you are playing in.