Phrygian cadence
A half cadence with a descending semitone step in the bass (in minor: iv6 → V), named after the Phrygian mode.
What it means
The Phrygian cadence is a half cadence in minor in which the subdominant in first inversion leads to the dominant, in terms of function theory s with the third in the bass to D (iv6–V). In A minor, the D minor sonority stands above the bass note F and moves on to the E major sonority. Characteristic is the bass movement: a semitone step downward, from the sixth to the fifth degree.
Characteristic is that the bass is led to the dominant not by a falling fifth but by a downward semitone step.
Musical use
The cadence has its name from its origin. In the Phrygian mode, the second degree lies only a semitone above the finalis, and the typical closing formula of this mode leads the bass with a downward semitone step to the finalis, while an upper voice rises to it by a whole tone. In major-minor tonality this has become a half cadence: the sonority on which the turn ends is now the dominant, no longer the tonic.
In Baroque music the Phrygian cadence is widespread, especially as the close of slow middle movements in minor that pass directly into a fast movement. It ends open and leads onward, instead of concluding. In the voice leading, bass and upper voice move apart in contrary motion from the sixth to the octave, which gives the turn its particular breadth.
The Phrygian cadence is to be distinguished from the ordinary half cadence, in which the bass usually leads upward from the subdominant in root position to the dominant.
The cadence often occurs in Baroque music at the end of slow middle movements, which then remain open on the dominant and lead directly into the following fast movement. Its name refers to the Phrygian mode, in which the downward semitone step to the finalis is characteristic.
Performance practice
Give the semitone step in the bass weight — it carries the effect. Keep the dominant sonority at the end open and without a closing gesture, for usually a further movement follows. And take some time before the final sonority; the turn demands breadth, not haste.