Chords in the key of C Sharp and D flat major
The chord chart below lists all the common traids and 
four note extended chords belonging to the key of C 
Sharp and D flat major major. Roman numerals indicate 
each chords position relative to the scale.

C Sharp major scale notes: C# D# E# F# G# A# B# C#
D flat major scale notes: Db Eb F Gb Ab Bb C Db
Major key chord sequence: Maj min min Maj Maj min dim
I	ii	iii	IV	V	vi	vii
C#maj	D#min	E#min	F#maj	G#maj	A#min	B#dim
C#maj7	D#min7	E#min7	F#maj7	G#7	A#min7	B#m7b5
I	ii	iii	IV	V	vi	vii
Dbmaj	Ebmin	Fmin	Gbmaj	Abmaj	Bbmin	Cdim
Dbmaj7	Ebmin7	Fmin7	Gbmaj7	Ab7	Bbmin7	Cm7b5
Common chord progressions in C sharp major
I - IV - V	C# - F# - G#
I - vi - IV - V	C# - Am# - F# - G#
ii - V - I	D#m7 - G#7 - C#maj7
Common chord progressions in D flat major
I - IV - V	C# - F# - G#
I - vi - IV - V	C# - Am# - F# - G#
ii - V - I	D#m7 - G#7 - C#maj7