A rondeau (French: [ʁɔ̃do]; 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 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 verse with a refrain. The rondeau is believed to have originated in dance songs involving singing of the refrain by a group alternating with the other lines by a soloist. The term "Rondeau" is used both in a wider sense, covering older styles of the form which are sometimes distinguished as the triolet and rondel, and in a narrower sense referring to a 15-line style which developed from these forms in the 15th and 16th centuries. The rondeau is unrelated to the much later instrumental dance form that shares the same name in French baroque music, which is more commonly called the rondo form in classical music.