Cdim7 chord on ukulele
Cdim7 is the diminished seventh chord: C, Eb, Gb and A (1–b3–b5–bb7). On ukulele, the diagram shape is 2 3 2 3, with Eb in the bass.
On the ukulele, the high reentrant G makes every shape light — and with four strings, every note is exposed. In this Cdim7 voicing the bass is Eb and the shape runs from fret 2 to 3. Its soft nylon strings sound warm and mellow, light enough to float gently over a song.
Notes and formula of Cdim7
Notes in Cdim7: C – Eb – Gb – AFormula: 1 – b3 – b5 – bb7In 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
Between two neighbouring chords it acts as a half-step stair: in C → C#° → DmDmDmDm it is the little step that pushes the music forward. In practice it is a passing chord — you barely notice it, but you feel the motion.
See also
Part of the Sevenths family.