Space plays and stops
- Notes and intervals
- A#M3C##m3E#m3G#4C#
- Extends
- A# Dominant 7
A# Dominant #9, written A#7#9, is built from A#, C##, E#, G# and C#: the root, major 3rd, 5th, minor 7th and sharp 9th.
Its 3rd and 7th, C## and G#, 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 A#7#9 as its tritone substitute.