C dominant thirteenth

C13

Also written C7(13) · Cdom13

NotesC · E · G · B♭ · D · A
Formula1 · 3 · 5 · ♭7 · 9 · 13
C1E3G5D9A13B♭♭7
All its notes, from the root

The dominant 13th: 1–3–♭7–9–13, with the 5th and the 11th usually left out. V of F major. In a rootless voicing the 13th (A) stands where the 5th would be — that one note is the whole difference between C9 and C13.

How pianists voice C13

Nobody plays a jazz chord in root position. These are the shapes that actually get played — the same ones Cadenza shows when you play the chord.

Shell Left hand

C1E3B♭♭7

1 · 3 · ♭7 — root, 3rd and 7th: the three notes that say what the chord is. Left hand, low; everything else is colour.

Rootless A From the 3rd

E3A13D9B♭♭7

3 · 13 · ♭7 · 9 — no root: the bass player has it. The left-hand voicing of modern jazz piano.

Rootless B From the 7th

D9E3A13B♭♭7

♭7 · 9 · 3 · 13 — the other half of the pair. A and B alternate through a ii–V–I so the hand barely moves. Without C underneath, the same keys read as B♭maj7(♯11) — the bass turns them into C13.

Drop 2 Two hands

A13C1E3B♭♭7

13 · 1 · 3 · ♭7 — close position with the second voice from the top dropped an octave: wider, warmer, the standard for chord melody.

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