C7 Chord on Ukulele
C7 = C – E – G – A# (Root, Major 3rd, Perfect 5th, Minor 7th)
A chord is the same notes however you stack them, and which one sits at the bottom changes how it sounds. The chord builder puts each of C7's notes in the bass in turn, names the result, and plays it.
Hear every inversion of C7 →C7 is arguably even easier to reach than C major: only the A string is fretted, at the first fret instead of the third, with the index finger, while the G, C, and E strings stay open. It's a striking example of how little movement separates a plain major triad from its dominant seventh on this instrument — one string, and only by two frets closer to the nut. Some beginners actually meet C7 before C major, since a few method books introduce it as the even-easier-to-reach shape first.
As the dominant seventh built on C, this chord functions as the V7 in the key of F, giving it a strong pull toward F major whenever a progression needs that resolution. Its sound sits between C major's calm and G7's sharper bite — a milder tension, since its own root note anchors so much of the open-string ring that it doesn't feel as unsettled as some seventh chords do. It's also common in twelve-bar-blues-style ukulele playing, where the tonic chord of a blues progression is very often voiced as a dominant seventh rather than a plain major triad. Because three of its four strings ring completely open, C7 keeps almost all of plain C major's bright, unfretted resonance while adding the seventh's extra color — a rare case on this instrument where a seventh chord loses none of its triad's characteristic openness.
Fingerings
Open Position
How to Practice It
Because it's genuinely a one-finger chord at a very low fret, C7 is a good candidate for practicing fast pivots — try C major to C7 and back, noticing that only the A string's fret number changes (three down to one), which trains the ear to hear how a seventh alters a chord without touching its root, third, or fifth. From there, C7 to F is worth isolating since it's the cadence this chord is built for. Because the fretted note sits so close to the nut, keep the fretting finger's pressure light — over-pressing at the first fret is a common way beginners accidentally pull the pitch sharp on such a short scale length. It's also worth practicing C7 in a slow blues shuffle rhythm rather than a plain strum, since that context is where this particular voicing turns up most often outside a straightforward C7-to-F resolution.
Common Progressions
- V7 – I (C7 – F)
- I – IV – V7 (F – Bb – C7, in the key of F)
- ii – V7 – I (Gm – C7 – F)
- Blues-style turnarounds often treat every chord in a I-IV-V loop as a dominant seventh, C7 included.
FAQ
- What's the difference between C major and C7 on ukulele?
- Only the A string's fret changes — third fret for major, first fret for the dominant seventh — making C7 an even lower, easier reach than the already-simple C major shape.
- What key does C7 resolve into?
- F major — C7 is the V7 chord in the key of F, so it's the natural setup chord right before an F resolution.
- Does C7 show up outside the key of F?
- Yes — it's also common in blues-style playing, where the tonic chord of a progression is often voiced as a dominant seventh from the start rather than a plain major triad.
- Why does C7 use the index finger rather than another finger?
- Using the index finger keeps the middle and ring fingers free to pre-position for whatever comes next, which matters most in a fast-moving progression where C7 is a brief passing chord rather than a place to rest.
- Does C7 lose any of C major's open, ringing sound?
- Barely — three of its four strings stay completely open, the same as plain C major, so C7 keeps nearly all of that chord's bright resonance while adding the seventh's mild tension on the fretted A string alone.
- Where else does this exact one-finger C7 shape get used?
- It's a common building block in ukulele blues shuffles and turnarounds, where a I7-IV7-V7-style progression treats every chord in the cycle as a dominant seventh rather than reserving that color for a single cadence.
- Should a beginner learn C7 before or after C major?
- After is standard practice, since C major establishes the basic strum and open-chord feel first, but the two are close enough in shape that learning C7 shortly afterward reinforces rather than complicates that foundation.
C7 on other instruments: C7 on Guitar, C7 on Piano. Related: how chords are built, chord finder.