B-flat minor seventh chord (Bbm7)
The B♭ minor seventh chord (B♭m7) is a minor seventh chord: a minor triad with a minor seventh on top, B♭, D♭, F and A♭ (root, minor third, perfect fifth and minor seventh).
It is the ii7 in A♭ major and the vi7 in D♭ major; its relative is D♭ major seventh, and F dominant seventh leads into it as its V7.
Below: voicings, notes on the fretboard, ukulele, piano, inversions and progressions.
How to play B♭ minor seventh on guitar
There are 2 guitar voicings.
Frets from the 6th string to the 1st: x = not played, 0 = open string.
- Voicing 1: x-1-3-1-2-1, barre at fret 1, with B♭ in the bass (fingers x-1-3-1-2-1).
- Voicing 2: 6-8-6-6-6-6, movable E-shape barre chord at fret 6, with B♭ in the bass.
Notes of the B♭ minor seventh chord on the fretboard
B♭ minor seventh has 4 notes: B♭, D♭, F and A♭. This is where they fall on each string, from the nut to the 12th fret (fret number in parentheses):
- String 6 (E): F (1) · A♭ (4) · B♭ (6) · D♭ (9)
- String 5 (A): B♭ (1) · D♭ (4) · F (8) · A♭ (11)
- String 4 (D): F (3) · A♭ (6) · B♭ (8) · D♭ (11)
- String 3 (G): A♭ (1) · B♭ (3) · D♭ (6) · F (10)
- String 2 (B): D♭ (2) · F (6) · A♭ (9) · B♭ (11)
- String 1 (E): F (1) · A♭ (4) · B♭ (6) · D♭ (9)
Formula and intervals of B♭ minor seventh
Its formula is 1-♭3-5-♭7; in semitones from the root, 0-3-7-10.
- B♭: Root, the note that gives the chord its name
- D♭: Minor third (m3), 3 semitones above B♭
- F: Perfect fifth (P5), 7 semitones above B♭
- A♭: Minor seventh (m7), 10 semitones above B♭
B♭ minor seventh on ukulele
- Ukulele (G C E A): 1-1-1-1, barre at fret 1; it sounds A♭, D♭, F and B♭.
B♭ minor seventh on piano
- Keys: B♭4, D♭5, F5 and A♭5.
Inversions of B♭ minor seventh
Each inversion puts a different note in the bass.
- Root position: B♭, D♭, F and A♭, with B♭ in the bass.
- First inversion (B♭m7/D♭): D♭, F, A♭ and B♭, with D♭ in the bass.
- Second inversion (B♭m7/F): F, A♭, B♭ and D♭, with F in the bass.
- Third inversion (B♭m7/A♭): A♭, B♭, D♭ and F, with A♭ in the bass.
Keys that use B♭ minor seventh
B♭ minor seventh appears in 6 major and minor keys.
| Key | Degree | Function |
|---|---|---|
| A♭ major (4 flats) | ii7 | Supertonic |
| G♭ major (6 flats) | iii7 | Mediant |
| D♭ major (5 flats) | vi7 | Submediant |
| B♭ minor (5 flats) | i7 | Tonic |
| F minor (4 flats) | iv7 | Subdominant |
| E♭ minor (6 flats) | v7 | Dominant |
Progressions with B♭ minor seventh
- Jazz ii–V–I in A♭ major (ii7–V7–Imaj7): B♭m7 – E♭7 – A♭maj7
B♭ minor seventh or A♯ minor seventh?
B♭ minor seventh (B♭m7) and A♯ minor seventh (A♯m7) are the same chord with two names: they sound the same and use the same frets.
The spelling depends on the key: it is written B♭ minor seventh in flat keys and A♯ minor seventh in sharp keys.
Frequently asked questions
What notes are in the B♭ minor seventh chord?
B♭, D♭, F and A♭: root, minor third, perfect fifth and minor seventh. Its formula is 1-♭3-5-♭7.
Which keys use B♭ minor seventh?
Mainly as the ii7 in A♭ major and the vi7 in D♭ major. In total it appears in 6 major and minor keys.
Is A♯ minor seventh the same chord as B♭ minor seventh?
Yes: A♯ minor seventh and B♭ minor seventh sound the same and are played the same way. It is written B♭ minor seventh in flat keys and A♯ minor seventh in sharp keys.
What is the relative of B♭ minor seventh?
D♭ major seventh: they share three of their four notes. In the key where D♭ major seventh is Imaj7, B♭ minor seventh is vi7; in a major key, the minor seventh chords are ii7, iii7 and vi7.