C seven sharp nine

C7#9 Piano Voicings

C7#9 is an altered dominant famous from rock and bebop alike. The clash between the major third and the sharp ninth gives it a gritty, bluesy tension.

Drill C7#9 in all 12 keys

The notes in C7#9

  • C R
  • E 3
  • G 5
  • Bb ♭7
  • Eb ♯9

C7#9 voicings on piano

Each voicing is the exact shape the trainer drills. Press play to hear it — as a block chord or rolled note by note.

Root Position

C · E · G · Bb · Eb R · 3 · 5 · ♭7 · ♯9

Shell Voicing

C · E · Bb R · 3 · ♭7

Rootless A

E · G · Bb · Eb 3 · 5 · ♭7 · ♯9

Rootless B

Bb · Eb · E · G ♭7 · ♯9 · 3 · 5

Where C7#9 fits in a ii-V-I

C7#9 is an altered dominant famous from rock and bebop alike. The clash between the major third and the sharp ninth gives it a gritty, bluesy tension.

The fastest way to internalise C7#9 is to drill it in context across all 12 keys until the shape is automatic.

Practice the full ii-V-I progression

C7#9 — frequently asked questions

What notes are in C7#9?

C7#9 contains C, E, G, B♭ and D♯ — root, third, fifth, flat seventh and sharp ninth.

Why is C7#9 called the Hendrix chord?

Jimi Hendrix made the dominant 7#9 voicing iconic in rock; the sharp ninth grinding against the major third gives it its signature bite.