Bb7 Bb dominant seventh chord
- Notes
- Bb D F Ab
- Formula
- 1 3 5 b7
- Semitones
- 0 4 7 10 above the root
- Also written
- A#7 (A# C## E# G#)
- Other symbols
- Bbdom7
Bb to D is a major third (4 semitones), D to F is a minor third (3 semitones), F to Ab is a minor third (3 semitones). A dominant seventh is a major triad plus a minor seventh (Ab, 10 semitones above Bb). It is the V chord that leads back home, and the basic chord of the blues.
Bb7 on the piano
Root position from Bb4: Bb4, D5, F5, Ab5. Middle C is C4.
Bb7 on the guitar
Standard tuning (E A D G B E). Strings run low E on the left to high e on the right, frets downwards; × is a muted string, ○ an open string, and each dot shows the note it sounds, with the root in blue-green. Every shape below has Bb as its lowest note.
x 1 3 1 3 1 (low E to high e)
Sounds Bb2 F3 Ab3 D4 F4
6 8 6 7 6 6 (low E to high e)
Sounds Bb2 F3 Ab3 D4 F4 Bb4
The barre shapes are movable: an E-shape chord's root is the note under your first finger on the low E string, an A-shape chord's root is the note on the A string. Slide the same grip up or down to play dominant seventh chords on other roots.
Inversions of Bb7
An inversion puts a note other than the root in the bass. The name is what semicord's chord finder calls those notes played bottom to top; a slash name like C/E means a C chord with E in the bass.
| Position | Notes, bass first | Named | Listen |
|---|---|---|---|
| Root position | Bb D F Ab | Bb7 | |
| 1st inversion | D F Ab Bb | Bb7/D | |
| 2nd inversion | F Ab Bb D | Bb7/F | |
| 3rd inversion | Ab Bb D F | Bb7/Ab |
Where Bb7 fits
Bb7 is V7 in Eb major, V7 in Eb minor. Its D and Ab are a tritone apart (6 semitones). In Eb major the D usually rises a half step to Eb and the Ab falls a half step, which is why Bb7 pulls so strongly towards Eb.