Authentic cadence
Dominant to tonic; with the root in the bass and the tonic on top, the strongest close.
What it means
The authentic cadence is the closing turn from the dominant to the tonic, in function-theoretical terms D–T (V–I), usually with the seventh as D7–T. It is the strongest and most unambiguous cadence formation of tonal music, because in it the leading tone is led to the root and the tension of the tritone resolves.
Musical use
How strongly an authentic cadence works depends on the position. If both chords stand in root position and the root lies in the upper voice of the closing chord, one speaks of a perfect cadence — it seems final and is used at the ends of movements and pieces. If, by contrast, the third or fifth lies on top, or one of the chords stands in inversion, the close seems less complete; one then speaks of an imperfect authentic cadence, which suits interior closes.
The voice leading is fixed: the bass leaps from the root of the dominant into that of the tonic, the leading tone rises to the root, the seventh falls to the third. Frequently a cadential six-four chord precedes the cadence, delaying the dominant.
The authentic cadence is to be distinguished from three related turns. The plagal cadence leads from the subdominant to the tonic, without a leading tone, and seems soft. The half cadence ends on the dominant and stays open.
The authentic cadence is the most important closing turn of major-minor tonality and determines the end of the great majority of pieces between the Baroque and Romanticism. Its force rests on two motions that work together: the falling fifth in the bass from dominant to tonic and the leading tone of the upper voice, which strains a semitone upward into the root. If one of these elements is missing, for instance with the third in the upper voice or with inversions, the close is felt as less perfect.
Performance practice
Give the dominant weight and the tonic calm — the effect lies in the resolution, not in the loudness of the closing chord. Lead the leading tone and the seventh audibly into their goals. And when shaping, distinguish between perfect and imperfect closes: not every close should sound like the end.