What C7 is built from
Counting up in semitones from C:
| Note | Interval | Semitones from root |
|---|---|---|
| C | root | 0 |
| E | major third | 4 |
| G | perfect fifth | 7 |
| B♭ | minor seventh | 10 |
Move all four of those the same distance and you get the same chord on another root — that is what the dominant seventh formula 0 – 4 – 7 – 10 means.
How to play C7
Leave the low E string out. The top E string rings open. Nothing is higher than fret 3, so it sits in first position.
This voicing leaves the fifth, G, out. Six strings and only five of them useful here; the fifth is the note that gives way, and the chord still reads as C7 without it.
All four strings are played. The G, C and E strings ring open. Nothing is higher than fret 1, so it sits in first position.
Play C, E, G and B♭ together. That is three white keys and one black.
Numbers in the grids are frets. Where a number is printed beside a grid, that is the fret the top row stands for; otherwise the thick bar at the top is the nut. A circle above a string means play it open, a cross means leave it out.
Guitar, string by string
| Guitar string | Stopped at | Sounds |
|---|---|---|
| low E | not played | — |
| A | fret 3 | C |
| D | fret 2 | E |
| G | fret 3 | B♭ |
| B | fret 1 | C |
| top E | open | E |
Ukulele, string by string
| Ukulele string | Stopped at | Sounds |
|---|---|---|
| G | open | G |
| C | open | C |
| E | open | E |
| A | fret 1 | B♭ |
C7 on the stave
The same four notes written on a treble stave, spelled the way a dominant seventh is spelled — one letter for every other step, with whichever accidental reaches the pitch. That is why it reads C, E, G and B♭, and not the same sounds written some other way.
Which keys C7 belongs to
| Key | Relative minor | Degree |
|---|---|---|
| F major | D minor | V7 |
Each row is a key whose scale contains every note of C7. A major key and its relative minor use the same seven notes, so the chord belongs to both.
Chords that sit next to C7
The seven triads built on the scale of F major. These are the chords C7 is most often played alongside, because they are made from the same seven notes. The small numeral is the degree each one stands on.
Other chords on C
Same root, different notes above it.
Chords straight off a recording
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