Chord & FretC7 · Electric guitar
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. Hit play below.
Listen first
What you just heard
Why does it sound unfinished? Inside C7, two notes are at odds: E and A#. Now listen to the arpeggio, one note at a time 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 electric guitar a chord needs only a few clear notes — the amp sustains them and fills the space, so you mute the strings you are not playing and let the tone carry the rest. So grab the first position below — 1 open string to help you; 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
Chord & Fret Pro maps over 200,000 voicings and inversions — hear and play them all.
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. Translation: wherever it shows up, the music is about to move. 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 · open in Chord & Fret
Identify Chord — Found a shape on your own fretboard? The app names it back · try 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. Typically, not a rule.
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 fits entirely — 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 · use it 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 · use 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.
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. No ads, no trackers.