C9 chord on ukulele
C9 is the dominant ninth chord: C, E, G, Bb and D (1–3–5–b7–9). On ukulele, the diagram shape is 3 0 0 5, with C in the bass.
On the ukulele, the high reentrant G makes every shape light — and with four strings, every note is exposed. In this C9 voicing the bass is C and the shape runs from fret 3 to 5, ringing 2 open strings. Because this instrument has fewer strings than C9 has notes, one note, usually the fifth, is normally dropped without losing the chord's identity. Its soft nylon strings sound warm and mellow, light enough to float gently over a song.
Notes and formula of C9
Notes in C9: C – E – G – Bb – DFormula: 1 – 3 – 5 – b7 – 9In the formula, the numbers count steps of the major scale starting from the note that names the chord; "b" lowers a half step, "#" raises one — and a slash names the bass note.
Where to use it
Blues, funk, choro and broader dominants.
See also
Part of the Extended family.