The B♭ Minor 7th chord is a four-note chord made up of B♭, D♭, F, and A♭. It is built from a root, minor third, perfect fifth, and minor seventh.
Construction
| Note | Interval | Degree |
|---|---|---|
| B♭ | Root | 1 |
| D♭ | Minor 3rd | ♭3 |
| F | Perfect 5th | 5 |
| A♭ | Minor 7th | ♭7 |
B♭ Minor 7th Inversions
| Position | Notes |
|---|---|
| Root Position | B♭ – D♭ – F – A♭ |
| 1st Inversion | D♭ – F – A♭ – B♭ |
| 2nd Inversion | F – A♭ – B♭ – D♭ |
| 3rd Inversion | A♭ – B♭ – D♭ – F |
Key Signature
A chord has no key signature of its own, but the B♭ Minor 7th is the tonic (i) chord of Bb Minor, which shares the signature of its relative major, Db Major — 5 flats (B♭, E♭, A♭, D♭, G♭).
Order of flats
Flats are added in a fixed order — the reverse of the sharp order. Each new flat key adds the next flat on the list.
Mnemonic: Battle Ends And Down Goes Charles’ Father
Chords in the Key of B♭ Minor
These are the triads built on each degree of the B♭ minor scale:
How B♭ Minor 7th functions in a key
The same chord takes on a different harmonic role depending on the key it appears in. Here is where B♭ Minor 7th sits diatonically across the common keys:
- In D♭ major, B♭ Minor 7th is the vi chord — the tonic.
- In B♭ minor, B♭ Minor 7th is the i chord — the tonic.
- In A♭ major, B♭ Minor 7th is the ii chord — a predominant.
- In F minor, B♭ Minor 7th is the iv chord — a predominant.
- In G♭ major, B♭ Minor 7th is the iii chord — a mediant / color chord.
- In E♭ minor, B♭ Minor 7th is the v chord.
Same Notes, Other Names
The notes B♭ – D♭ – F – A♭ aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell: