Descripción en Youtube:
Guillaume de Machaut (1300-1377) was a French composer of the Ars Nova period in the 14th century. His music used very expressive melodies, with an interplay of duple and triple meter.
Composers during his time began to compose more secular music, including in the new genre the polyphonic chanson.
Here is an example of one, written in a low register, suitable for 3 men's voices.
Oxford Camerata
Jeremy Summerly