C13 Chord on Guitar
C13 = C – E – G – A# – D – A (Root, Major 3rd, Perfect 5th, Minor 7th, Major 9th, Major 13th)
C13 is the fullest extension in the dominant family, theoretically stacking all the way up through the thirteenth — but no six-string guitar voicing plays all six chord tones of a thirteenth chord at once. The version fingered at the eighth fret keeps root, third, flat seventh, and thirteenth, which is the standard real-world compromise every guitarist relying on this shape actually plays.
The full formula runs C-E-G-A#-D-A, but the ninth and eleventh drop out of the guitar voicing, leaving the four notes that do the real work: the root and third establish the major-dominant identity, the flat seventh supplies the pull toward resolution, and the thirteenth — really a major sixth an octave up — gives the chord its rich, jazz-club color on top. It's the sound most associated with sophisticated jazz comping right before a cadence, richer than a plain C7 but without the harmonic murkiness a fully-voiced 9th, 11th, and 13th stacked together would create.
Fingerings
Barre (8th fret)
How to Practice It
Because the thirteenth sits a whole octave above where a plain sixth would land in a simpler chord, getting the top note to ring clearly matters — it's the note doing the most work to distinguish C13 from an ordinary C7, so a muted or buzzed top string quietly turns this rich jazz voicing back into a plain dominant seventh without the player necessarily noticing why the chord sounds flatter than expected. Practicing the shift from a plain C7 into C13 and back is a good way to isolate exactly which finger is responsible for that top color note.
Common Progressions
- Dm7 – G7 – C13 (ii7 – V7 – I13, a jazz turnaround landing on a rich tonic)
- C13 – F (V13 – I, the fullest possible dominant pull)
- C13 – C7 – F6 (moving from rich color down to a simpler resolution)
- G13 – C13 – F13 (a jazz progression stacking 13th chords throughout)
FAQ
- Does C13 actually contain all six notes of its formula?
- No — the theoretical stack runs through the ninth and eleventh as well as the thirteenth, but a practical guitar voicing keeps only root, third, flat seventh, and thirteenth, since fitting every extension onto six strings without muddying the sound isn't possible or musically necessary.
- What does the thirteenth actually add to the sound?
- It's the same pitch class as a major sixth, just voiced an octave higher, and it's the note primarily responsible for the rich, sophisticated jazz color that separates C13 from a plainer C7 — remove it and the chord loses most of what makes it sound like a 13th at all.
- Why isn't the ninth included in this voicing?
- With only six strings and four notes already prioritized (root, third, seventh, thirteenth), something has to give, and the ninth is the extension least essential to a dominant chord's core identity, so it's the one guitarists routinely leave out in practice.
- Is C13 harder to play cleanly than C9?
- It asks for similar coordination — a partial barre plus a couple of independently fretted notes — so the difficulty is comparable; the main added challenge is making sure the top note (the thirteenth) rings clearly, since it's doing more work to define the chord's color than any single note in the C9 voicing.
- Where does C13 typically appear in a chord chart?
- Almost always right before a resolution to F, functioning as an especially rich-sounding V chord — jazz standards frequently substitute a 13th chord for a plain seventh specifically at these cadence points to add a more polished, professional color.
- Can C13 substitute for a plain C7 anywhere in a progression?
- In most jazz and jazz-influenced contexts, yes — since the added extensions color the chord without changing its underlying dominant function, a 13th chord can generally stand in for a plain seventh wherever that seventh was already resolving normally.
- How does C13 compare to C11 in terms of harmonic clarity?
- C13 keeps the third and therefore reads clearly as a major-dominant chord, while C11 drops the third and lands in more ambiguous, sus4-adjacent territory — despite C13 technically being the larger extension, it's actually the more harmonically definite of the two.
Related: how chords are built, chord finder.