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 triad, the lowest three notes of the seventh chord are known as the root, third, and fifth.
**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
The **major seventh chord** consists of major triad and a major seventh. The chord symbol for a major seventh chord includes the name of the root plus the capital Greek letter delta (Δ) followed by the number 7.
**Example 2.** Major seventh chord.
![[example seventh chords major.png]]
![[example seventh chords major.mp3]]
### Dominant
The **dominant seventh chord** (also known as a major-minor seventh chord) consists of a major triad and a minor seventh. Its chord symbol includes the name of the root followed by the number 7.
**Example 3.** Dominant seventh chord.
![[example seventh chords dominant.png]]
![[example seventh chords dominant.mp3]]
### Minor
The **minor seventh chord** consists of a minor triad and minor seventh. Its chord symbol includes the name of the root followed by a lowercase m and the number 7.
**Example 4.** Minor seventh chord.
![[example seventh chords minor.png]]
![[example seventh chords minor.mp3]]
### Half-diminished
The **half-diminished seventh chord** consists of a diminished triad and minor seventh. Its chord symbol includes the name of the root followed by a degree symbol with a diagonal slash and the number 7.
**Example 5.** Half-diminished seventh chord.
![[example seventh chords half-diminished.png]]
![[example seventh chords half-diminished.mp3]]
### Fully diminished
The **fully diminished seventh chord** (or more simply, a diminished seventh chord) consists of a diminished triad and a diminished 7. Its chord symbol includes the name of the root followed by a degree symbol and the number 7.
**Example 6.** Fully diminished seventh chord.
![[example seventh chords fully diminished.png]]
![[example seventh chords fully diminished.mp3]]