Chord · C Dominant 7th
C7 Chord
C7 is C, E, G and Bb — tense; wants to resolve down a fifth. Blues and jazz workhorse.
C7 on every instrument
The same 4 notes, 6 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.
What C7 is made of
C7 (C seventh) is built from the notes C, E, G, Bb, with the interval pattern 1, 3, 5, b7.
Stack 1, 3, 5 and b7 on a root of C and you get C, E, G and Bb. That interval recipe is what makes the chord a seventh chord — move the same shape to another root and the character travels with it, which is why D7 sounds like a transposed C7.
Dominant 7th: Tense; wants to resolve down a fifth. Blues and jazz workhorse.
Spelling: the notes above are written the way a score would write them, not simplified to the nearest piano key. That is why this chord is spelled with B♭ rather than its enharmonic equivalent.
Keys that contain C7
All 4 notes sit inside the scale of 2 keys. The roman numeral marks the degree the chord is rooted on.
Major keys
Minor keys
Other chords on C
Same root, different colour.
The same seventh shape, moved
The identical interval recipe, built on other roots.
Questions people ask about C7
- What notes are in the C7 chord?
- C7 is made of C, E, G and Bb — the 1, 3, 5 and b7 degrees of a seventh chord built on C.
- What keys use the C7 chord?
- Every note of C7 belongs to 2 keys: F Major (V), D Minor (VII). The roman numeral is the scale degree the chord is rooted on.
- How do you play C7 on guitar and piano?
- This page shows C7 on guitar, piano, ukulele, bass, mandolin and banjo — 13 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
Learn the theory behind it
Why C7 behaves the way it does — the guides that explain the chord instead of just spelling it.