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 augmented ninth.
Construction
C 7♯9 = Root + Major 3rd + Perfect 5th + Minor 7th + Minor 3rd = 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 3rd | ♭3 |
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 no sharps or flats.
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 (C7♯9) contains 5 notes: C, E, G, Bb, D#. Formula: R-M3-P5-m7-A9.
How is C7♯9 used in music?
C7♯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 C7♯9?
C7♯9 uses scale degrees 1-3-5-b7-#9, giving it its distinctive sound.