C9 arpeggio & chord for gypsy jazz
The C9 arpeggio is built from the notes C (R), E (3), G (5), B♭ (♭7), D (9). On Haute Gitanerie you can see it across the whole guitar neck — contained position boxes, long diagonal forms, and its parent scale (C Mixolydian) — with note names in English (C D E) or solfège (Do Ré Mi).
The C9 chord
The C9 chord voicing uses those same notes (C (R), E (3), G (5), B♭ (♭7), D (9)). Switch the fretboard to Chords to see gypsy-jazz voicings for C9, or keep Arpeggio to practise the tones one at a time — same shape, two ways to hear it.
How to practise the C9 arpeggio
Start with a contained position box near the low strings, then move it up the neck fret by fret, or follow a diagonal form for a two-octave sweep in the manouche style. Every note is labelled with its interval (R, 3, 5, ♭7, 9), so you always know where the root, third, fifth sit.