Un ballo in maschera

Un ballo in maschera (A Masked Ball) is an Italian opera in three acts. The music was written by Giuseppe Verdi. The libretto was written by Antonio Somma. It is based on Eugène Scribe's Gustave III ou Le Bal Masqué. 

The opera was first performed at the Teatro Appollo in Rome, on February 17, 1859. One of Verdi's richest  middle-period works, it relates the events surrounding the assassination of King Gustav III of Sweden, but because of censorship, the story was transposed to 17th century Boston, with Gustav becoming an English governor, Richard of Warwick. Nowadays, most productions present the opera in its original Swedish setting. 

Principal characters

 Gustavo/Riccardo, King of Sweden in love with Amelia- tenor
 Amelia, a courtier - soprano
 Renato, a courtier and Amelia's husband - baritone
 Ulrica, a fortune teller - mezzo-soprano
 Oscar, a page - soprano
 Samuel, conspirator - bass
 Tom, conspirator - bass
 Silvano, conspirator - baritone

Sources
 The Complete Dictionary of Opera & Operetta, James Anderson, Wings Books, 1993. 

Category:Compositions by Giuseppe Verdi
Category:1850s operas