Origins of opera
"Dafne" by Jacopo Peri was the earliest composition considered opera, as understood today, although with only five instrumental parts it was much more like a chamber opera than either the preceding intermedi or the operas of Claudio Monteverdi a few years later. It was written around 1597, largely under the inspiration of an elite circle of literate Florentine humanists who gathered as the "Camerata". Significantly, "Dafne" was an attempt to revive the classical Greek drama, part of the wider revival of antiquity characteristic of the Renaissance. The members of the Camerata considered that the "chorus" parts of Greek dramas were originally sung, and possibly even the entire text of all roles; opera was thus conceived as a way of "restoring" this situation. The libretto was by Ottavio Rinuccini, who had written some of the 1587 Medici intermedi, in which Peri had also been involved; Rinuccini appears to have recycled some of the material, at least from the scene illustrated at right. Most of the music for "Dafne" is lost (the libretto was printed and survives), but one of Peri's many later operas, "Euridice", dating from 1600, is the first opera score to have survived to the present day.
Libretto
The opera libretto from its inception (ca. 1600) was written in verse, and this continued well into the 19th century, although genres of musical theatre with spoken dialogue have typically alternated verse in the musical numbers with spoken prose. Since the late 19th century some opera composers have written music to prose or free verse libretti. Much of the recitatives of George Gershwin's opera "Porgy and Bess", for instance, are merely DuBose and Dorothy Heyward's play "Porgy" set to music as written – in prose – with the lyrics of the arias, duets, trios and choruses written in verse.