The plot of Il Trovatore is enough to get almost anyone to go to the opera. Without giving too much away, there's true love, vengeance, mistaken identity, bitter irony, suicide, Gypsies, swordfights, and the famous "Anvil Chorus," which sounds like . . . oh, Google it. And one of the characters is both a military officer and a troubadour, as though 19th-century Italian audiences needed a reason for a hero to bust into song.