Perfect authentic cadence
A chord progression where the dominant chord is followed by the tonic chord ( V-I or V-i). The " V" represents the chord based on the fifth step of the scale and the " I" represents the chord based on the first step of the scale (" i" being the minor version of the chord based on the first step of the scale. The dominant to tonic progression ( V-I) represents the strongest sound of all cadences. In the tonality of " C" major, an authentic cadence would be the dominant ( V) G major chord ( GB D) moving to the tonic ( I) C major chord ( CE G).In a perfect authentic cadence, the dominant chord in root position is followed by that of the tonic in root position, and according to some theorists, the cadence is not " perfect " unless the uppermost voice is the tonic in the final chord.Also Authentic Cadence.