Perfect cadence
An authentic cadence with the tonic in the soprano and bass.
What it means
The perfect cadence is the strongest form of the authentic close. Three conditions belong to it: the dominant leads to the tonic, D–T (V–I); both chords stand in root position; and in the closing chord, the root of the tonic lies both in the bass and in the top voice. When all three are fulfilled, the close seems final.
Musical use
Each of the three conditions contributes to the closing strength. The connection of dominant and tonic supplies the leading-tone tension and its resolution. The root position of both chords lets the bass leap in a falling fifth, the strongest bass movement of all. The root in the top voice also closes the melody, so that nothing remains open.
If one of these conditions is missing, the close becomes weaker. If the third or the fifth lies on top in the closing chord, or if one of the chords stands in inversion, one speaks of an imperfect cadence. This gradation is an important means of formal structuring: imperfect closes structure within a section, the perfect one concludes it or the piece.
The top voice mostly reaches the root stepwise — upward from the leading tone or downward from the second degree. Often a cadential six-four chord precedes the close, delaying the dominant.
Bear in mind that the terms are not used uniformly in the textbooks; sometimes “perfect” is related only to the top voice, sometimes to all three conditions.
The perfect cadence counts as the strongest closing effect of tonal music: both outer voices land on the root, the bass with a falling fifth, the top voice mostly with the leading tone or a downward step of a second. The distinction helps in formal analysis, because movement endings almost always close perfectly, while internal caesuras often do not.
Performance practice
Lead the top voice deliberately into the root and the bass into the falling fifth. Take the closing chord calmly and intonate it carefully; in a perfect close every deviation stands out. And save this closing form for the points where the music actually ends.