Chord & FretC7 · Cavaquinho
Say this out loud: "one, two..." — and stop right there. Uncomfortable, isn't it? The sentence is hanging. That discomfort has a sound: C7 is a sentence without a period. Press play down there.
Listen first
What you just heard
Why does it sound unfinished? Inside C7, two notes are arguing: E and A#. Play the arpeggio again, no rush and catch the second and the last note — the distance between them is the tritone, the tensest interval tonal music knows. C and G keep the house standing while those two argue inside it. And an argument, you know, demands a resolution.
Now it's your hands' turn
On the cavaquinho, four steel strings tuned D–G–B–D pack the chord into a small, bright space — every finger counts. So grab the first position below; the position marked with ⭐ is the easiest to play. Now the experiment that explains this chord better than any explanation: play C7, hold it for one breath, then play F. Felt the door close? Do it again. That relief is the reason this chord exists.
2 more shapes of this chord on the neck
Part of over 200,000 voicings and inversions in Chord & Fret Pro — see and play every one.
Precision Tuner — Before you play these shapes, get in tune — chromatic tuner and reference tones · see it in Chord & Fret
The other positions earn their keep in blues and jazz, where this chord is practically the official language; learn them one at a time.
Left-handed? Mirror's right here
What is C7?
C7: C Major with Seventh. The notes are C, E, G, Bb (fixed-do: Do, Mi, Sol, Si♭) — the degrees 1–3–5–b7.
Where this chord lives
Its job is fixed: C7 is a dominant, and dominants live as VII7 in D minor, V7 in F major. Plainly: where it enters, the song is about to leave the room. A chart full of 7th chords is a song that won't sit still.
Transpose & Capo — Need it in another key? Move the whole chart and find the easiest capo · try it in Chord & Fret
Identify Chord — Found a shape on your own fretboard? The app names it back · use it in Chord & Fret
Where it tends to go
Treating C7 as the home chord (I) of its key, it tends to go toward the pre-dominant (Dm / F) or the dominant (G / B°) — and the dominant pulls back home. It's a tendency, not a law.
Every shape of C7 lives in Chord & Fret Pro — 4 instruments, 16 tunings, 41 chord types and 57 scales, in every key. Start free. Unlock everything with Pro. 100% offline. Made by musicians, no ads.
When you want to go further
For soloing, C Mixolydian (C D E F G A Bb · 1 2 3 4 5 6 b7: the major scale with a lowered seventh — the blues accent); C Lydian dominant (C D E F# G A Bb · 1 2 3 #4 5 6 b7: a mixolydian with a raised fourth: the dominant in formalwear) cover the whole chord. And look at the first swap on the list below: that's the famous tritone substitution, the twin dominant living three whole steps from here, the one arrangers reach for when they want to arrive at the same place by a prettier road.
C Mixolydian
4 more scale positions on the neck
Chord & Fret Pro maps over 35,000 mapped scale shapes — hear and play them all.
The same C Mixolydian in its main shapes along the neck — pick whichever position sits under your hand. The rings mark the guide notes (the 3rd and 7th) that carry this chord's color.
Improvising in context
To improvise over C7 as home, the C Mixolydian scale covers it whole — it contains every note of the chord. And when the dominant (G) pulls back, the leading tone B is the note that wants to resolve home.
Swaps that work:
- Gb7 — Tritone substitution (shared 3rd–7th tritone)
- Gm7 — Forms a II–V: precede with this ii
- Dbdim7 — Passing diminished (ascending)
Reharmonize — Want richer substitutions? Reharmonize the progression in a tap · open in Chord & Fret
The same chord, dressed for jazz
Jazz Lab — Drop 2, drop 3 and shell in any key — the Jazz Lab opens them all · try it in Chord & Fret
You already know how this sentence ends. The period after C7 is called F — go there and close it with your own fingers.