Seventh chord

A seventh chord is a chord consisting of a triad plus a note forming an interval of a seventh above the chord's root. When not otherwise specified, a "seventh chord" usually means a dominant seventh chord: a major triad together with a minor seventh. However, a variety of sevenths may be added to a variety of triads, resulting in many different types of seventh chords.

In its earliest usage, the seventh was introduced solely as an embellishing or nonchord tone. The seventh destabilized the triad, and allowed the composer to emphasize movement in a given direction. As time passed and the collective ear of the western world became more accustomed to dissonance, the seventh was allowed to become a part of the chord itself, and in some modern music, jazz in particular, nearly every chord is a seventh chord. Additionally, the general acceptance of equal temperament during the 19th century reduced the dissonance of some earlier forms of sevenths.

Classification of seventh chords

Seventh (chord)

In music, the seventh factor of a chord is the note or pitch seven scale degrees above the root or tonal center. When the seventh is the bass note, or lowest note, of the expressed chord, the chord is in third inversion  Play .

Conventionally, the seventh is fourth in importance to the root, fifth, and third, with third inversion being the third strongest inversion and the seventh variably minor or major. In jazz chords and theory, the seventh is required in a seventh chord, and the fifth is often omitted in preference for it and the chord quality determining third, chord extensions, and additions.

The seventh is most commonly minor or major (in C, B♭ or B♮) or less often diminished or augmented (B=A or B♯=C).

Resolution

In the common practice period the "strict resolution" the chord seventh is stepwise downward. For example, the seventh of the dominant seventh chord, resolving to tonic, moves downward to the third of the following chord.

See also

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