The C♯ 7♭9 chord is a five-note chord made up of C♯, E♯, G♯, B, and D. It is built from a root, major third, perfect fifth, minor seventh, and minor ninth.
Construction
C♯ 7♭9 = Root + Major 3rd + Perfect 5th + Minor 7th + Minor 2nd = C♯ · E♯ · G♯ · B · D
| Note | Interval | Degree |
|---|---|---|
| C♯ | Root | 1 |
| E♯ | Major 3rd | 3 |
| G♯ | Perfect 5th | 5 |
| B | Minor 7th | ♭7 |
| D | Minor 2nd | ♭9 |
Key Signature
A chord has no key signature of its own, but the C♯ 7♭9 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♯ 7♭9 — Frequently Asked Questions
What is the C♯ 7♭9 chord on piano?
The C♯ 7♭9 chord contains the notes C♯ – E♯ – G♯ – B – D. On piano, play these notes together to sound the chord.
What notes are in the C# 7♭9 chord?
The C# 7♭9 chord (C#7♭9) contains 5 notes: C#, F, G#, B, D. Formula: R-M3-P5-m7-m9.
How is C#7♭9 used in music?
C#7♭9 is used in jazz, fusion, and contemporary music to add harmonic color. It appears as a dominant or tonic chord depending on context.
What is the scale degree formula for C#7♭9?
C#7♭9 uses scale degrees 1-3-5-b7-b9, giving it its distinctive sound.