Space plays and stops
- Notes and intervals
- F#M3A#2CM3E
- Extends
- F# Dominant 7
F# Dominant b5, written F#7b5, is built from F#, A#, C and E: the root, major 3rd, flat 5th and minor 7th.
Its 3rd and 7th, A# and E, 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 F#7b5 as its tritone substitute.