B-flat major seventh chord (Bbmaj7)
The B♭ major seventh chord (B♭maj7) is a major seventh chord: a major triad with a major seventh on top, B♭, D, F and A (root, major third, perfect fifth and major seventh).
It is the Imaj7 in B♭ major and the IVmaj7 in F major; its relative is G minor 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♭ major 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-1-3-2-3-1, barre at fret 1, with B♭ in the bass (fingers x-1-3-2-4-1).
- Voicing 2: 6-8-7-7-6-6, movable E-shape barre chord at fret 6, with B♭ in the bass.
Notes of the B♭ major seventh chord on the fretboard
B♭ major 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 (5) · B♭ (6) · D (10)
- String 5 (A): A (0) · B♭ (1) · D (5) · F (8) · A (12)
- String 4 (D): D (0) · F (3) · A (7) · B♭ (8) · D (12)
- String 3 (G): A (2) · B♭ (3) · D (7) · F (10)
- String 2 (B): D (3) · F (6) · A (10) · B♭ (11)
- String 1 (E): F (1) · A (5) · B♭ (6) · D (10)
Formula and intervals of B♭ major seventh
Its formula is 1-3-5-7; in semitones from the root, 0-4-7-11.
- B♭: Root, the note that gives the chord its name
- D: Major third (M3), 4 semitones above B♭
- F: Perfect fifth (P5), 7 semitones above B♭
- A: Major seventh (M7), 11 semitones above B♭
B♭ major seventh on ukulele
- Ukulele (G C E A): 2-2-1-1, barre at fret 1; it sounds A, D, F and B♭.
B♭ major seventh on piano
- Keys: B♭4, D5, F5 and A5.
Inversions of B♭ major 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♭maj7/D): D, F, A and B♭, with D in the bass.
- Second inversion (B♭maj7/F): F, A, B♭ and D, with F in the bass.
- Third inversion (B♭maj7/A): A, B♭, D and F, with A in the bass.
Keys that use B♭ major seventh
B♭ major seventh appears in 4 major and minor keys.
| Key | Degree | Function |
|---|---|---|
| B♭ major (2 flats) | Imaj7 | Tonic |
| F major (1 flat) | IVmaj7 | Subdominant |
| G minor (2 flats) | IIImaj7 | Mediant |
| D minor (1 flat) | VImaj7 | Submediant |
Progressions with B♭ major seventh
- Jazz ii–V–I in B♭ major (ii7–V7–Imaj7): Cm7 – F7 – B♭maj7
B♭ major seventh or A♯ major seventh?
B♭ major seventh (B♭maj7) and A♯ major seventh (A♯maj7) 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♭ major seventh in flat keys and A♯ major seventh in sharp keys.
Frequently asked questions
What notes are in the B♭ major seventh chord?
B♭, D, F and A: root, major third, perfect fifth and major seventh. Its formula is 1-3-5-7.
Which keys use B♭ major seventh?
Mainly as the Imaj7 in B♭ major and the IVmaj7 in F major. In total it appears in 4 major and minor keys.
Is A♯ major seventh the same chord as B♭ major seventh?
Yes: A♯ major seventh and B♭ major seventh sound the same and are played the same way. It is written B♭ major seventh in flat keys and A♯ major seventh in sharp keys.
What is the difference between B♭ major seventh and a dominant seventh chord?
The seventh: in B♭ major seventh (B♭, D, F and A) it is major, a half step below the octave, while in a dominant seventh it is minor. That is why B♭ major seventh sounds stable, like a chord of rest, and a dominant seventh wants to resolve.