Playable, correctly spelled, and not how the chord is normally voiced. Right now this is the shapes that put a ninth, eleventh or thirteenth below the root.
C69 is C, E, G, A and D — C6 with the ninth added as well.
It sounds wide and entirely at rest. The modern way to voice a tonic when a triad is too bare and a maj7 too pointed.
Tonic — it commits to nothing.

| C | E | G | A | D |
|---|---|---|---|---|
| 1 | 3 | 5 | 6 | 9 |
Also written C6/9, C6add9 or C six nine. The same chord either way; which spelling you meet depends on who wrote the chart.
Five notes and four fingers, so something has to go. Keep E (it fixes the quality) and A and D (what the symbol is about). Let G and C go, in that order — a perfect fifth says nothing the root has not, and in a band the bass has the root.
Play C69 as a shell — root, third and seventh — and the spare string takes the #11 (F#).
All 9 common shapes as fret numbers, lowest string first. Hover or tap one to see it drawn.
How you get to it. The turn that lands on C69 is Dm7 to G7 — the ii and the V of C — and G7 shares its third and seventh with Dm7, so the hand barely moves between them.
In which keys. Every note of C69 belongs to C major (the I), D minor (the ♭VII), E minor (the ♭VI), F major (the V), G major (the IV) and A minor (the ♭III).
C69 is every note of the C major pentatonic, and nothing else. It also sits inside C major, C mixolydian, C lydian and C lydian dominant.
Each of those is a page: the scale across the neck, and the chords it harmonises into — which is where C69 sits in it. Every scale.
Change one note of C69 and you have Cmaj9 (the sixth becomes the major seventh), Cmaj13 (add the major seventh), Cm69 (the major third becomes the minor third), Cadd9 (drop the sixth), C6 (drop the ninth) or C9 (the sixth becomes the flat seventh).
C69 is a major chord — root, major third, fifth. Major chords on every root.
The common shapes and the derived voicings come from different places, and both are explained in how this site is built.
Shows each chord the way this style would voice it, and marks which of its alternatives belong to the idiom.