L'Orfeo, SV 318 sometimes called La favola d'Orfeo, is a late Renaissance/early Baroque opera, by Claudio Monteverdi, with libretto by Alessandro Striggio. It is based on the Greek legend of Orpheus, and tells the story of his descent to Hades and his fruitless attempt to bring his dead bride Eurydice back to the living world. It was written in 1607 for a court performance. While the honour of the first ever opera goes to Jacopo Peri's Dafne, and the earliest surviving opera is Euridice (also by Peri), L'Orfeo has the honour of being the earliest surviving opera that is still regularly performed today. Its score was published by Monteverdi in 1609 and again in 1615. After the composer's death in 1643 the opera went unperformed for many years, and was largely forgotten until a revival of interest in the late 19th century led to a spate of modern editions and performances. At first these tended to be unstaged versions within institutes and music societies. After the Second World War most editions started to use period instruments. In his published score Monteverdi lists around 41 instruments to be deployed, with distinct groups of instruments used to depict particular scenes and characters. Composed at the point of transition from the Renaissance era to the Baroque, L'Orfeo employs all the resources then known within the art of music, with particularly daring use of polyphony. The work is not orchestrated as such; in the Renaissance tradition instrumentalists followed the composer's general instructions but were given considerable freedom to improvise. This separates Monteverdi's work from the later opera canon, and makes each performance of L'Orfeo a uniquely individual occasion.
