Chord (music)

In music and music theory, a chord (from the middle English cord, short for accord) is three or more different notes or pitches sounding simultaneously, or nearly simultaneously, over a period of time. For example, if you simultaneously play any three (or more) keys of a piano, you have just played a chord. Likewise, if you simultaneously play three or more strings of a guitar, you have just played a chord on the guitar. Every chord is given a specific name, based on the notes that constitute the chord and the distances, or intervals, between them.

Augmented sixth chords

:Main article: Augmented sixth chord.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

An augmented sixth chord is a chord which contains two notes which are separated by an augmented sixth (or, by inversion, a diminished third - though this inversion is rare in compositional practice). The augmented sixth is generally used as a dissonant interval which resolves by both notes moving outward to an octave.

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

In Western music, the most common use of these chords is to resolve to a dominant chord in root position (that is, a dominant triad with the root doubled to create the octave to which the augmented sixth chord resolves), or to a tonic chord in second inversion (a tonic triad with the fifth doubled for the same purpose). In this case, the tonic note of the key is included in the chord, sometimes along with an optional fourth note, to create one of the following (illustrated here in the key of C major):

~ ~ ~ ~ ~ ~ ~ ~ ~ ~

• Italian Augmented Sixth Chord: A flat, C, F sharp
• French Augmented Sixth Chord: A flat, C, D, F sharp
• German Augmented Sixth Chord: A flat, C, E flat, F sharp