It is often said that the opera-libretto is a specific genre, a purely artistic and artificial idiom whose main characteristics lie both in its strong codification and in its heavy dependence on key-words ; those indeed are needed in order to maintain in performance the understanding of a text otherwise difficult to fully perceive acoustically. Did such a language already exist in seventeenth- (and eighteenth-) century opera, or was it only made up in the nineteenth century ? How can one testify to its influence ? To what extent does it differ from straight drama idioms ? The present article assesses the research that has been undertaken to find answers to those questions, and shows how methods derived from quantitative linguistics have been used jointly with other methods of linguistic analysis.
