Seventh chords

a chord consisting of a triad plus a note forming an interval of a seventh above the chord's root

major third, perfect fifth, and minor seventh (i.e. a major triad with an additional minor seventh); e.g. C–E–G–B♭

seventh chord composed of a root note, together with a minor third, a diminished fifth, and a diminished seventh; e.g. C–E♭–G♭–B𝄫

seventh chord in which the third is a major third above the root and the seventh is a major seventh above the root; e.g. CEGB

seventh chord in which the third is a minor third above the root and the seventh is a minor seventh above the root

chord composed of a root, minor third, diminished fifth and minor seventh (i.e. a diminished triad with an additional minor seventh)

seventh chord composed of a root, minor third, perfect fifth, and major seventh; e.g. C–E♭–G–B