Chords
Bb Dominant seventh
Bb · D · F · Ab
The dominant seventh — a major triad with a minor seventh. The chord that creates the pull home.
Also written Bbdom
Bb Dominant seventh
Bb · D · F · Ab
Voicings on the piano
| Voicing | Notes | Play it on your instrument |
|---|---|---|
| Closed, root position | Bb3 · D4 · F4 · Ab4 | |
| Open (drop 2) | F3 · Bb3 · D4 · Ab4 | |
| Shell | Bb3 · D4 · Ab4 | |
| Rootless | D4 · G4 · Ab4 · C5 |
Tap a key or a fret to hear it.
Anatomy
Bb Dominant seventh (Bb7) contains the notes Bb · D · F · Ab, each with a role measured as an interval from the root.
Read on: how triads are built · seventh chords
Inversions
An inversion of Bb Dominant seventh puts a chord tone other than Bb in the bass; the name after the slash is that bass note.
Where it lives
The keys and the scales Bb Dominant seventh belongs to.
In which keys
Bb Dominant seventh is diatonic to 3 keys; the numeral is its degree and the label its harmonic function.
Scales that contain it
Bb Dominant seventh fits inside these scales, each built on Bb.
- Bb MixolydianBb · C · D · Eb · F · G · Ab
- Bb Lydian DominantBb · C · D · E · F · G · Ab
- Bb Phrygian DominantBb · Cb · D · Eb · F · Gb · Ab
- Bb Half-Whole DiminishedBb · Cb · Db · D · E · F · G · Ab
- Bb Mixolydian PentatonicBb · D · Eb · F · Ab
- Bb Lydian Dominant PentatonicBb · D · E · F · Ab
- Bb Mixolydian b6Bb · C · D · Eb · F · Gb · Ab
- Bb Lydian MinorBb · C · D · E · F · Gb · Ab
Understanding the Bb Dominant seventh chord
Names and symbols
Bb7 is the chord symbol for Bb Dominant seventh; it is also written Bbdom.
How it is built
On Bb it is Bb · D · F · Ab, stacking 1P · 3M · 5P · 7m. The major triad supplies stability and the minor seventh supplies tension.
Inside it, the third and the seventh are a tritone apart. That tritone is the entire engine: the third wants to rise a semitone and the seventh to fall a semitone, and where they land defines the key.
How it is used
As the V7 of a key it is the strongest possible signal of where home is. As the I7 and IV7 of a blues it loses that obligation entirely and simply becomes the sound — twelve-bar blues is built from dominant sevenths that never resolve conventionally.
Because its tritone is shared with the dominant seventh a tritone away, Bb7 can be substituted for that chord and still resolve convincingly. That is tritone substitution, and it is how a chromatic bass line gets built.
Learn this properly
Chapter 10: Chords: Triads and SeventhsCommon questions
- What notes are in Bb7?
- Bb7 contains Bb · D · F · Ab. Name any set of notes with the chord identifier.
- Why does a dominant seventh want to resolve?
- Its third and seventh form a tritone. The third rises and the seventh falls by a semitone each, closing onto the tonic chord.
- What is tritone substitution?
- Replacing a dominant seventh with the one a tritone away. Both contain the same tritone, so both resolve to the same place — but the substitute moves the bass down a semitone instead of a fifth.
- What notes are in the Bb Dominant seventh chord?
- The Bb Dominant seventh chord contains the notes Bb · D · F · Ab: the root Bb with the intervals 1P, 3M, 5P, 7m stacked above it. Play them together for the chord or one after another for an arpeggio. The lowest note is normally Bb, but any chord tone can take the bass in an inversion.
- What intervals make up the Bb Dominant seventh chord?
- Measured from Bb, the Bb Dominant seventh chord stacks the intervals 1P, 3M, 5P, 7m. The quality of the third and of the seventh, if there is one, is what gives the chord its character; the rest of the notes colour it. Every interval in the formula links to its own page, with its sound.