The name "suspended" derives from an early polyphonic technique developed during the common practice period, in which a stepwise melodic progress to a harmonically stable note in any particular part was often momentarily delayed, or suspended, by extending the duration of the previous note. The resulting unexpected dissonance could then be all the more satisfyingly resolved by the eventual appearance of the displaced note. In traditional music theory, the inclusion of the third in either chord would negate the suspension, so such chords would be called added ninth and added eleventh chords instead.