The first operas were in Italian. The form spread throughout Europe and the world, and there are now operas in virtually every language.
The first opera is generally agreed to have been Dafne, by Jacopo Peri. The libretto is in Italian.
'opera' is Italian for 'work' and an abbreviation of 'opera in musica'.
In almost every language it is called opera.
Beethoven's opera Fidelio is in German.
it comes from the Italian language
Italian
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Italian
The language of the libretto (text of the opera) was Italian.
Italian is the language from which the word 'opera' comes. It's a feminine noun in Italian. It includes among its different translations 'work, opera [as a piece of music], opera [as the theater in which the music is performed], and deed'. It's pronounced 'OH-peh-rah'.
As far as can be established - Italian. The first opera composed is accepted as 'Daphne' or 'Dafne' first performed in 1598 during Carnival at the home of Jacopo Corsi in Florence. The music was by Jacopo Peri to a libretto by Ottavio Rinuccini. It is recognized as such because it was the first of a series of similar pieces that established the form of early 17th century Italian opera. The score does not survive.
A Singspiel is closest to a ballad opera. It is a form of German-language music drama, now regarded as a genre of opera.