Principal forms of music and poetry in 14th-and 15th-century France.
Three forms predominated. The rondeau followed the pattern ABaAabAB ; A (a) and B (b) represent repeated musical phrases; capital letters indicate repetition of text in a refrain, while lowercase letters indicate new text. The ballade employed the pattern aabC . The virelai used the pattern AbbaA . The trouvère Adam de la Halle (b. 0441; 1250) wrote the first polyphonic settings of the formes fixes . Guillaume de Machaut wrote both text and music for many monophonic and polyphonic chanson s in the formes fixes . Later composers, including Guillaume Dufay , favoured the rondeau.