Rondeau (forme fixe)

A rondeau (plural rondeaux) is a form of medieval and Renaissance French poetry, as well as the corresponding musical chanson form. Together with the ballade and the virelai it was considered one of the three formes fixes, and one of the verse forms in France most commonly set to music between the late 13th and the 15th centuries. It is structured around a fixed pattern of repetition of material involving a refrain. The rondeau is believed to have originated in dance songs involving alternating singing of the refrain elements by a group and of the other lines by a soloist. The term "Rondeau" is today used both in a wider sense, covering several older variants of the form – which are sometimes distinguished as the triolet and rondel – and in a narrower sense referring to a 15-line variant which developed from these forms in the 15th and 16th centuries. The rondeau is unrelated with the much later instrumental dance form that shares the same name in French baroque music, which is an instance of what is more commonly called the rondo form in classical music.

The older French rondeau or rondel as a song form between the 13th and mid-15th century begins with a full statement of its refrain, which consists of two halves. This is followed first by a section of non-refrain material that mirrors the metrical structure and rhyme of the refrain's first half, then by a repetition of the first half of the refrain, then by a new section corresponding to the structure of the full refrain, and finally by a full restatement of the refrain. Thus, it can be schematically represented as AB-aAab-AB, where "A" and "B" are the repeated refrain parts, and "a" and "b" the remaining verses. If the poem has more than one stanza, it continues with further sequences of aAab-AB, aAab-AB, etc.

In its simplest and shortest form, the rondeau simple, each of the structural parts is a single verse, leading to the eight-line structure known today as triolet, as shown in "Doulz viaire gracieus" by Guillaume de Machaut:

Doulz viaire gracieus,
de fin cuer vous ay servi.
Weillies moy estre piteus,
Doulz viaire gracieus,
Se je sui un po honteus,
ne me mettes en oubli:
Doulz viaire gracieus,
de fin cuer vous ay servi. 

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Wikipedia