and poems often practiced vegetarianism and abstention from sex, and refrained from eating eggs and beans—which came to be known as the Orphikos bios, or "Orphic way of life". The Derveni papyrus, found in Derveni, Macedonia (Greece) in 1962, contains a philosophical treatise that is an allegorical commentary on an Orphic poem in hexameters, a theogony concerning the birth of the gods, produced in the circle of the philosopher Anaxagoras, written in the second half of the fifth century BC. Fragments of the poem are quoted making it "the most important new piece of evidence about Greek philosophy and religion to come to light since the Renaissance". The papyrus dates to around 340 BC, during the reign of Philip II of Macedon, making it Europe's oldest surviving manuscript. The historian William Mitford wrote in 1784 that the very earliest form of a higher and more cohesive ancient Greek religion was manifest in the Orphic poems. W. K. C. Guthrie wrote that Orpheus was the founder of mystery religions and the first to reveal to men the meanings of the initiation rites. Post-Classical interpretations Classical music The Orpheus motif has permeated Western culture and has been used as a theme in all art forms. Early examples include the Breton lai Sir Orfeo from the early 13th century and musical interpretations like Jacopo Peri's Euridice (1600, though titled with his wife's name, the libretto is based entirely upon books X and XI of Ovid's Metamorphoses and therefore Orpheus's viewpoint is predominant). Subsequent operatic interpretations include: Claudio Monteverdi's L'Orfeo (1607) Luigi Rossi's Orfeo (1647) Marc-Antoine Charpentier's La descente d'Orphée aux enfers H.488 (1686). Charpentier also composed a cantata, Orphée descendant aux enfers H.471, (1683) Christoph Willibald Gluck's Orfeo ed Euridice (1762) Joseph Haydn's last opera L'anima del filosofo, ossia Orfeo ed Euridice (1791) Franz Liszt's symphonic poem Orpheus (1854) Jacques Offenbach's operetta Orphée aux Enfers (1858) Igor Stravinsky's ballet Orpheus (1948) David Maslanka's work for two bassoons and marimba Orpheus (1977) Two operas by Harrison Birtwistle: The Mask of Orpheus (1973–1984) and The Corridor (2009) The Bulgarian Rousse State Opera commissioned and performed Orpheus: A Masque by John Robertson (2015) Fabio Mengozzi's electronic poem Orpheus (2022). Literature Rainer Maria Rilke's Sonnets to Orpheus (1922) are based on the Orpheus myth. Poul Anderson's Hugo Award-winning novelette "Goat Song", published in 1972, is a retelling of the story of Orpheus in a science fiction setting.