Isolde (Richard Wagner) References Bibliography McGinnis, Pearl Yeadon. The opera singer’s career guide: understanding the European Fach system, edited by Marith McGinnis Willis. (Scarecrow Press, 2010) Midgette, Anne (6 May 2007), "Home in the Range? Who Can Sing What". The New York Times. Retrieved 1 November 2012. Steane, J. B. "Fach" in The New Grove Dictionary of Opera, ed. Stanley Sadie (London, 1992) Opera terminology Music classification