The Added tone chord reference article from the English Wikipedia on 24-Jul-2004
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Added tone chord

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An added tone chord is a triadic chord with an extra "added" note, such as the added sixth. This includes chords with an added thirteenth and farther "extensions", but that do not include the intervening thirds as in an extended chord.

Suspended chords

A suspended chord is a chord in which the third is replaced or accompanied by either a fourth or a major second, although the fourth is far more common.

This type of sound is borrowed from the contrapuntal technique of suspension, where a note from a previous chord is carried over to the next chord, and then resolved down to the third or tonic, suspending a note from the previous chord. However, in a suspended chord the added tone does not necessarily resolve.

Suspended chords are most commonly found in folk music and popular music.

Contrast with sixth chord.