There is a legend that in Ancient Rome, one of the members of the Senate each his speech, whatever topic it may be, ended with the words: "furthermore, I think Carthage must be destroyed". These words can be defined as a constant refrain of all his speeches.
What is the refrain (in French refrain - chorus)?
The so-called section of a musical work, which is completely without any changes is repeated at least three times. A synonym of the refrain - the refrain in the song. The word "refrain" is used, generally, in relation to the form of a Rondo, which has its origin from the couplet of the song.
Not to be confused unison with the Reprise. They are similar, but the Reprise, though it sounds like a repetition of the exposition, sometimes is a repetition of inaccurate and, in addition, does not form a threefold repetition.