A# Tritone Substitution
ii – bII7 – I progression in A# major
A# Tritone Substitution — ii – bII7 – I
The A# ii–bII7–I tritone substitution (Cm – B – A#) replaces the dominant V with a chord a tritone away, creating a chromatic, mysterious color. With seventh voicings (Cm7 – B7 – A#Maj7), it delivers one of the most sophisticated sounds in jazz harmony.