(plural "rondeaux") the most long-lasting of the French formes-fixes, cultivated in the thirteenth, fourteenth, and fifteenth centuries; it has the form A B a A a b A B, where a capital letter designates a refrain text and lower case designates new text. Each of the two musical sections had a refrain text which came back at the end of the poem, but the two halves of the refrain had to be separable, for in the middle of the poem three statements of the opening music appeared together. Thus, the medial cadence marking the end of the first (A) section had to be able to lead forward to the contrasting B material or lead back to the beginning of the first section. Poets and musicians alike enjoyed playing with the subtle reinterpretation of material over the course of a piece generated by this elaborate structure. medieval French form of poetry and music. A form consisting of a repeated refrain and different material in between refrains