What is "ritornelle"

Ritornelle \Rit`or*nelle"\, Ritornello \Ri`tor*nel"lo\, n. [It. ritornello, dim. of ritorno return, fr. ritornare to return: cf. F. ritournelle.] (Mus.) (a) A short return or repetition; a concluding symphony to an air, often consisting of the burden of the song. (a) A short intermediate symphony, or instrumental passage, in the course of a vocal piece; an interlude.

n. (alternative form of ritornello English)