Triads contain three distinct notes. Adding a seventh creates four-note chord types. On guitar, a voicing may repeat notes or leave some out.
| Chord | Formula |
|---|---|
| Major / minor triad | 1 3 5 / 1 ♭3 5 |
| Diminished / augmented | 1 ♭3 ♭5 / 1 3 ♯5 |
| Major seventh | 1 3 5 7 |
| Dominant seventh | 1 3 5 ♭7 |
| Minor seventh | 1 ♭3 5 ♭7 |
| Half-diminished seventh | 1 ♭3 ♭5 ♭7 |
| Diminished seventh | 1 ♭3 ♭5 ♭♭7 |
The diminished seventh sounds like a major sixth in equal temperament, but its spelling describes its role in the chord. Ninths, elevenths, and thirteenths extend these relationships beyond the octave.
Pick up your guitar
Load G Mixolydian. Find degrees 1, 3, 5, and ♭7 to outline a G7 chord.