A seventh [[chords|chord]] consists of four notes that are stacked in thirds, comprising a triad plus an additional note known as the **seventh**. Like the [[triads|triad]], the lowest three notes of the seventh chord are known as the root, third, and fifth; the added note forms an interval of a seventh above the root.
**Example 1.** Seventh chord construction.
![[example seventh chords construction.png]]
## Types of Seventh Chords
There are five types (or qualities) of seventh chords used in the [[common practice]]: major, dominant, minor, half-diminished, and fully diminished. These are determined by the quality of the triads and sevenths they contain. As with [[triads]], the root and quality of a seventh chord can be identified using [[chord symbols]].
- [[major seventh chord]]
- [[dominant seventh chord]]
- [[minor seventh chord]]
- [[half-diminished seventh chord]]
- [[fully diminished seventh chord]]