A Forme fixé (English: fixed form) is any one of three fourteenth and fifteenth centuries French poetic forms, the ballade, rondeau and virelai. Each was also a musical form, generally a song, and all consisted of a complex pattern of repetition of verses and a refrain with musical content in two main sections.
All three forms can be found in thirteenth-century sources but a fifteenth-century source gives Philippe de Vitry as their first composer while the first comprehensive repertory of these forms was written by Guillaume de Machaut.[1] The formes fixés stopped being used in music around the end of the fifteenth century, although their influence continued, but in poetry they, especially the rondeau, continued to be used.[1]
Sometimes forms from other countries and periods are referred to as formes fixés. These include the Italian fourteenth century madrigal and later ballata and barzelletta, the German bar form, Spanish 13th century cantiga, and the later canción, and villancico.[1]
David Fallows. "Formes Fixes", Grove Music Online, ed. L. Macy (accessed September 16, 2006), grovemusic.com (subscription access).