| The first great opera by Giuseppe Verdi. The usual name Nabucco is short for the full name Nabucodonosor, Italian for the Assyrian* king Nebuchadnezzar. It tells the story of the captivity of the Jews, when Jerusalem was captured by forces led by Nebuchadnezzar's ambitious supposed daughter Abigaille. Inevitably there are love triangles between Assyrian and Jewish leaders.
There are four acts. The most loved song of the opera is in Act Three, the Chorus of the Hebrew Slaves, or Va, pensiero. When the opera was first performed in 1842, Milan and much of northern Italy were under Austrian rule, and this poignant, yearning chorus of a people dreaming of freedom in their homeland made the young Verdi a hero of Italian nationalism.
King Nabucco (baritone) has two daughters, Fenena and Abigaille (soprani). Fenena is a hostage among the Jews in Jerusalem, now under siege by Assyrian forces, and is in love with the Jewish commander Ismaele (tenor), nephew of the king. Abigaille also loves Ismaele, and when she leads the Assyrian warriors into the Temple she offers to share the throne she intends on taking. He refuses, but when the Jewish high priest Zaccaria (bass) threatens to kill their hostage Fenena, Ismaele rescues her and returns her to the advancing Assyrians, and is therefore reviled as a traitor.
So. That's just Act One. In Act Two, Jerusalem and the Temple having been despoiled and the Jews taken into captivity, the ambitious Abigaille learns that she is not Nabucco's true daughter, but a child of a slave. Nevertheless she seeks to hide this fact and displace Fenena as her father's heir. When Nabucco is reported killed in battle the high priest of Baal (bass) proclaims Abigaille ruler; but Nabucco proves more resilient and returns. He announces that he is God. God strikes him down and he goes mad (you might remember he eats grass at this point). Abigaille has another go at being ruler, but more cautiously calls herself regent now, and follows Dad round with a death warrant for her sister, trying to get him to sign it.
This is when the Hebrews are pining for their homes, and sing Va, pensiero ("Go, thoughts, on golden wings"), by the rivers of Babylon, because Abigaille and the high priest of Baal have condemned them all to death. This includes Fenena, who has converted because of her love of Ismaele, much to the distress of Nabucco, who is now once more in his right senses, but kept a prisoner by his supposed daughter. It ends with various miracles occurring, Abigaille taking poison and begging forgiveness, and so on; and I'm sure I've skipped a lot of the detail.
The opera was Verdi's third, after Oberto (1839) and Un giorno di regno (1840), being produced at La Scala, Milan, on 9th March 1842, with libretto by Temistocle Solera. The title role was sung by Giorgio Ronconi (1810-1890), and Abigaille was Giuseppina Strepponi (1815-1897), later to be Verdi's wife. Ismaele was Corrado Miraglia. The first foreign performance was in Lisbon in 1843. In London it premiered under the title Nino at Her Majesty's on 3rd March 1846, and in New York at the Astor Opera House on 4th April 1848.
Concise Oxford Dictionary of Opera
Everyman's Dictionary of Music
Met opera synopsis at www.metopera.org/synopses/nabucco.html
Performance history at opera.stanford.edu/Verdi/Nabucco/history.html
live broadcast from the Met earlier tonight
* The Italian lyrics seem to refer to the enemy as Assyrians more than Babylonians, the term we would now use. | 
