How to Play C7#9 on Piano
The C Dominant 7th Sharp 9 chord sounds gritty and electric. It stacks 5 notes: C – E – G – Bb – D#.
The Hendrix chord. The raised ninth is the minor third spelled an octave up, so the chord holds the major and minor third at once: exactly the ambiguity a blues singer bends between.
Notes in C7#9
| Note | Interval | RH | LH |
|---|---|---|---|
| CC4 | RootR | ||
| EE4 | Major 3rd3 | ||
| GG4 | Perfect 5th5 | ||
| BbBb4 | Minor 7thb7 | ||
| D#D#5 | Augmented 9th#9 |
No fingers are listed against the written notes because no hand holds this chord as written. The playable split is beside this table.
How to Play
Two hands, because it is wider than an octave
Written out, C7#9 spans 15 semitones, so nobody grabs it in one hand. Play it the way it is actually played:
- Left hand: C as the bass, finger 5.
- Right hand: E, G, Bb, D#, fingers 1-2-3-5.
Shell voicing
Root, third and seventh: C, E, Bb, left hand 5-3-1. Those three notes are what make this chord the chord it is, so a jazz player holds them in the left hand and keeps the right hand free for the melody.
Where it sits
2 notes of this chord (Bb, D#) are on black keys, so play it a little further back on the keys than an all-white shape.
Opens a block chord drill for C7#9. More drills, from broken chords to inversions, are further down the page.
Practice Exercises
Play each one to hear it, then open it in the practice player, which shows the notes coming toward you and checks what you play on a MIDI keyboard or the on-screen piano.
Block Chord
Press all 5 notes (C, E, G, Bb, D#) at the same time. Hold for 4 beats, release, then repeat 8 times. Focus on pressing every key at exactly the same moment with even volume.
Broken Chord (Arpeggio)
Play each note one at a time. Go up, then back down:
C → E → G → Bb → D# → D# → Bb → G → E → C
Keep a steady rhythm. Once comfortable, try speeding up gradually.
Inversions and Slash Chords
The same 5 notes rearranged so a different one sits at the bottom. This is the same idea as a slash chord: C7#9/E is simply C7#9 with E in the bass. Learning to move between them is what stops your hand jumping around the keyboard.
| Inversion | Written | Notes | RH |
|---|---|---|---|
| Root position | C7#9 | C – E – G – Bb – D# | 1-2-3-4-5 |
| 1st inversion | C7#9/E | E – G – Bb – D# – C | 1-2-3-4-5 |
| 2nd inversion | C7#9/G | G – Bb – D# – C – E | 1-2-3-4-5 |
| 3rd inversion | C7#9/Bb | Bb – D# – C – E – G | 1-2-3-4-5 |
| 4th inversion | C7#9/D# | D# – C – E – G – Bb | 1-2-3-4-5 |
Two-Hand: Bass + Chord
Left hand: play C one octave lower as a single bass note. Right hand: play E, G, Bb, D#. Play the bass note first, then the chord, like a simple accompaniment pattern. Repeat until it feels natural.
When to use each slash chord
Puts the third in the bass, which is the usual way to walk a bass line by step between two chords a third apart.
Puts the fifth in the bass. This is the shape that keeps a pedal-like bass under a changing harmony, and the one most often written with a slash in pop and worship charts.
Puts the seventh in the bass, which pulls the bass line downward by step into the next chord.
Puts the highest chord tone in the bass. Rare, and worth knowing mostly so you can read it when it appears.
Chords You Can Play Instead of C7#9
These share most of their notes with C7#9, so any of them can stand in for it without breaking the harmony. Swapping one in is the quickest way to make a progression you already know sound different.
Dominant 7th Sharp 9 Chords in Every Key
The same shape moved to another root. Once you can hear what a dominant 7th sharp 9 chord does, the work left is finding it under the hand in the other eleven keys.
Other C Chords
Every other chord in the library built on C: what C7#9 becomes when a note is added, moved or taken away.