In a rare display of unanimous praise, international music critics rated this cycle one of the greatest operatic events of its time. Although Monteverdi played a truly important role in the development of opera, only few major opera houses have ventured to present these three Baroque masterpieces. Years of intensive study by conductor Nikolaus Harnoncourt, not only of the transmitted scores but also of the instruments used in Monteverdi's time, were necessary to provide a basis for the exceptionally high standard of the Zurich productions. Just how meticulously Harnoncourt and the celebrated stage director Jean-Pierre Ponnelle prepared themselves is made partly clear by the fact that the orchestra exclusively played original 17th-century instruments and specially-made copies for these productions. This in turn meant that each of the 39 members of the -awaited expansion of the standard opera repertoire had successfully been realized. What makes the Monteverdi cycle a unique project is the certainty that it can never again be repeated with quite the same quality and feeling.