Input (grade 13): Tristan und Isolde (Tristan and Isolde, or Tristan and Isolda) is an opera, or music drama, in three acts by Richard Wagner to a German libretto by the composer, based largely on the romance by Gottfried von Straßburg.
Output (grade 7): Tristan und Isolde (Tristan and Isolde) is an opera in three acts by Richard Wagner.