Radvanovskya play written has sung as Elvira and in a libretto largely written by who?
Sondra Radvanovsky: Sondra Radvanovsky (born April 11, 1969) is an American-Canadian soprano. Sondra Radvanovsky:  Her signature roles include Elvira in "Ernani", Leonora in "Il trovatore", Elena in "I vespri siciliani", Élisabeth in "Don Carlos", and the title role in "Norma". Il trovatore: Il trovatore (] ; Italian for "The Troubadour") is an opera in four acts by Giuseppe Verdi to an Italian libretto largely written by Salvadore Cammarano, based on the play "El trovador" (1836) by Antonio García Gutiérrez.
Salvadore Cammarano