Gymel
Medieval duet in thirds or sixths.
What it means
The gymel is a way of writing in the English music of the late Middle Ages in which one voice temporarily divides into two voices of the same range, led predominantly in parallel thirds or sixths. The name derives from the Latin gemellus, "twin-like", and refers to the division of one voice into two like lines.
Musical use
The gymel is remarkable above all for its sound. Whereas the continental polyphony of that time preferred fifths, octaves, and fourths as perfect sonorities and treated thirds as imperfect, the gymel rests precisely on thirds and sixths. This preference for the fuller, softer sound is described as a feature of the English music of that time and counts as one of the ways by which the third entered European music and finally became the basic building block of the texture.
At section ends the two voices usually converge into the unison or the octave, so that the parallel motion leads into a perfect closing sonority. This pattern — parallel thirds or sixths that open into the octave at the end or close in the unison — is widespread into later music.
The gymel stands in close connection with the faux-bourdon of the fifteenth century, which leads three voices in parallel first-inversion chords; both belong to the development in which the sound of the third established itself.
How far the gymel is to be understood as a genre in its own right or rather as a compositional practice is judged differently in scholarship.
As a tendency of English compositional technique the gymel reaches back to the thirteenth century; the surviving examples date mostly from the fifteenth and sixteenth centuries, for instance by John Dunstaple or in the Eton Choirbook. It is often regarded as a precursor of the fauxbourdon.
Performance practice
Sing the two voices as one sound: same length, same attack, shared phrasing. Intonate the thirds rather narrow so that the sonority becomes calm. And shape the closing turn into the unison or the octave deliberately — that is where the parallel motion resolves.