Space plays and stops
- Notes and intervals
- GbM3Bbm3Dbm3Fbm3G
- Extends
- Gb Dominant 7
Gb Dominant b9, written Gb7b9, is built from Gb, Bb, Db, Fb and G: the root, major 3rd, 5th, minor 7th and flat 9th.
Its 3rd and 7th, Bb and Fb, 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. C7, a tritone away, has the same two notes the other way up, so it can stand in for Gb7b9 as its tritone substitute.