The C♯ Major 9♯11 chord is a six-note chord made up of C♯, D♯, E♯, F♯♯, G♯, and B♯.
Construction
C♯ Major 9♯11 = Root + Major 2nd + Major 3rd + Diminished 5th + Perfect 5th + Major 7th = C♯ · D♯ · E♯ · F♯♯ · G♯ · B♯
| Note | Interval | Degree |
|---|---|---|
| C♯ | Root | 1 |
| D♯ | Major 2nd | 9 |
| E♯ | Major 3rd | 3 |
| F♯♯ | Diminished 5th | ♭5 |
| G♯ | Perfect 5th | 5 |
| B♯ | Major 7th | 7 |
Key Signature
A chord has no key signature of its own, but the C♯ Major 9♯11 is the tonic (I) chord of C# Major, whose key signature has 7 sharps (F♯, C♯, G♯, D♯, A♯, E♯, B♯).
F♯C♯G♯D♯A♯E♯B♯
Order of sharps
Sharps are added to a key signature in a fixed order. Each new sharp key adds the next sharp on the list.
F♯C♯G♯D♯A♯E♯B♯
Mnemonic: Father Charles Goes Down And Ends Battle
Chords in the Key of C♯ Major
These are the triads built on each degree of the C♯ major scale:
C♯ Major 9♯11 — Frequently Asked Questions
What is the C♯ Major 9♯11 chord on piano?
The C♯ Major 9♯11 chord contains the notes C♯ – D♯ – E♯ – F♯♯ – G♯ – B♯. On piano, play these notes together to sound the chord.