Space plays and stops
- Notes and intervals
- BbM3Dm3Fm3Abm3Cb
- Extends
- Bb Dominant 7
Bb Dominant b9, written Bb7b9, is built from Bb, D, F, Ab and Cb: the root, major 3rd, 5th, minor 7th and flat 9th.
Its 3rd and 7th, D and Ab, are its guide tones: they say what kind of chord it is, so voicings are built around them and the root is often left to the bass. E7, a tritone away, has the same two notes the other way up, so it can stand in for Bb7b9 as its tritone substitute.
In the progressions here, Bb7b9 is the V7♭9 of the Minor ii-V to Major Progression in Eb.