Sandra Warfield performed with the Zurich Opera, where in 1961 she sang Katerina in the world premiere of Martinů's "The Greek Passion". They returned to the United States, and the Metropolitan Opera, in the 1960s. Her performances at the Met included Ulrica in Giuseppe Verdi's "Un ballo in maschera", Berta in "The Barber of Seville" by Gioachino Rossini, Marcellina in "The Marriage of Figaro", Maddalena in "Rigoletto" by Verdi and Erda in Richard Wagner's "Siegfried", totaling 172 performances. She sang the role of Delilah in "Samson and Delilah", with Richard Tucker performing as Samson. In her farewell performance in January 1972, Warfield
Conservatorio Statale di Musica "Gioachino Rossini" Oliveri in Pesaro. Amongst its past Directors are the composers Carlo Pedrotti, Pietro Mascagni, Riccardo Zandonai and Franco Alfano. Mascagni's opera "Zanetto" had its world premiere at the conservatory in 1896. In his will, Rossini left virtually his entire estate to Pesaro, his native city, for the establishment of a free music school there with the provision that the legacy would only come to the city upon the death of his widow, Olympe Pélissier. In 1869, the year following Rossini's death, the city set up the association which would eventually become the "Liceo musicale Rossini". Olympe Pélissier died in 1878.