'Erismena', opera in a prologue and 3 acts, by Pier Francesco Cavalli. Original Italian libretto by Aurelio Aureli. Full score, copied in England by Robert Bargrave between 1656 and 1660, with the words in an anonymous English translation only.

The music of the prologue is known only from this manuscript, the text for which is an English translation of Cavalli's 'new' prologue of 1656. The music is skillfully adapted to the English words and the score appears to have been made with performance in mind. However, no production of an Italian opera in England has been recorded from the 17th century, although John Evelyn's diary for 5 Jan 1674 notes that "I saw an Italian opera in musique, the first that had been in England of this kind", which may possibly refer to Erismena. Although no title-page is now present (and in consequence no name of the opera, its composer or librettist), there are preliminaries with the 'Argument', and lists of the dramatis personae and scenes. Together with the fact that there are only three out of the expected four leaves to these preliminaries, this suggests that there was originally a title-page, which was already missing when the manuscript was bound. A later hand has added the supposed title 'Erimante' (one of the characters) at the head of fol. 3 (the list of dramatis personae). The contemporary binding has a red label on the spine (probably added or renewed in the 18th century) stating merely 'An opera in English'.

For an extensive discussion of this source and its history, see the introduction to the Bärenreiter edition of 2018, edited by Beth Glixon and Michael Burden.