Space plays and stops
- Notes and intervals
- C#M3E#m3G#m3Bm3D
- Extends
- C# Dominant 7
C# Dominant b9, written C#7b9, is built from C#, E#, G#, B and D: the root, major 3rd, 5th, minor 7th and flat 9th.
Its 3rd and 7th, E# and B, 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. G7, a tritone away, has the same two notes the other way up, so it can stand in for C#7b9 as its tritone substitute.
In the progressions here, C#7b9 is the V7♭9 of the Minor ii-V to Major Progression in F#.