Va, pensiero, sull'ali dorate;
Va, ti posa sui clivi, sui colli,
Ove olezzano tepide e molli
L’aure dolci del suolo natal!
Del Giordano le rive saluta,
Di Sïone le torri atterrate…
Oh mia patria sì bella e perduta!
Oh membranza sì cara e fatal!

Go, my thought, on wings of gold, go, alight on the cliffs, and on the hills,
Where, warm and gentle, the sweet breezes of our native land blow.
Greet the banks of the Jordan, the fallen towers of Zion…
Oh, my country, so lovely and lost! Oh, remembrance, so dear and despairing!

Arpa d’ôr dei fatidici vati
Perchè muta dal salice pendi?
Le memorie nel petto raccendi,
Ci favella del tempo che fu!
O simile di Solima ai fati
Traggi un suono di crudo lamento,
O t’ispiri il Signore un concento
Che ne infonda al patire virtù.

Golden harp of prophets and bards, why do you hang mute upon the willow?
Rekindle memories in our breast, speak to us of the time that was.
In memory of the fate of Jerusalem, sound a song of better lamentation;
Else may the Lord inspire in you harmonies that give us fortitude to bear our suffering.

The Danish philosopher Søren Kierkegaard is said to have been a frequent visitor to the Royal Opera at Copenhagen. Having bought his ticket, though, he would stay in the theatre lobby and listen to the performance rather than watch it on stage. The essential truth of an opera, he insisted, was in its music. The stage, the costumes, the enactment of a plot, and all other operatic trappings were merely unwanted distractions.

Kierkegaard probably said this in connection with Don Giovanni, the opera for which he had so much admiration and feeling. Yet when listening to the third Act of Nabucco, the opera that catapulted Verdi from obscurity to international fame, one begins to understand what Kierkegaard was talking about. Nabucco weaves delicately-told human stories into an epic tale of national humiliation and redemption, and its characters are sensitively and compellingly drawn. But it is not these that have given the opera such a special place amongst Verdi's works. Rather, it is the exquisitely quiet fervour of Verdi's music, and especially of Va pensiero, the poignant chorus of the Hebrew slaves on the banks of the Euphrates. The poetry of these words is beautiful, but it is far overshadowed by the grandiose evocative power of the music that Verdi composed for them.

Nabucco has taken on mythic proportions in the years since it was first performed, but its story is still essentially the story of Va pensiero. The chorus' nostalgic invocation of past national glories, its pathos-filled lamentation of present desolation, and its promise of redemption gave a spiritual boost to the Italy of the day, yet to find its unity, and dominated by France and Spain. Verdi once said that there was no human matter so great or powerful or abstract that it could not be given voice and form in melody and song. Va pensiero became the voice of the Risorgimento, the "rising up" of 19th-century Italians to freedom and unity, and gave expression to the upwelling of patriotic emotion and melancholic nostalgia amongst the masses who shared its aspirations. Even at Verdi's funeral in 1901, the procession was not escorted by music from one of one of his later masterworks. Instead, the music was va pensiero, sung spontaneously by the thousands on thousands of Italians lining the streets for the funeral.

This much is reasonably well known. What is not so well known is that without va pensiero, there would have been no Nabucco and - in all probability - no Verdi. This is how the story runs.

In 1840, just 18 months before Nabucco's premiere, Verdi's life was in ruins. Between 1838 and June 1840, his two children and then his beloved wife had died. And then, his opera Un giorno di regno, which he had forced himself to complete despite the emotional devastation into which his wife's death plunged him, was jeered from the stage and withdrawn in its second performance. Tormented by personal loss and unable to find consolation in his art, he came to a decision: he would never compose again.

Enter the impressario of La Scala: Bartolomeo Merelli. One cold dark winter evening, he dragged Verdi into his office at the theatre, and presented him with a libretto by Temistocle Solera, a "stupendous, magnificent, extraordinary" piece with exquisite verse. Despite Verdi's protests, Merelli sent him off with the libretto to read.

Verdi would later report that as he went home, he felt a very deep sadness fill his heart. He flung the manuscript on the table, and lay down. But sleep eluded him. Returning to the table, he found that the manuscript had opened in falling and gazing at the page, he read the words :

Va, pensiero, sull'ali dorate

Something about those lines arrested him, he would say, and he read through the verses that followed. They moved him deeply, capturing as they did the sorrow and courage of the Hebrews in a way that almost paraphrased the 137th Psalm. Quietened, he sat down and read the libretto. Once, twice, thrice, and again and again until he knew it by heart. For a while, he tried to be resolute in his determination to write no more, but he could not get Nabucco out of his head. Little by little, under Merelli's gentle persuasion, he wrote a verse here, a phrase there, until the opera was composed. On 9 March, 1842, Nabucco debuted at La Scala, Milan. It opened to an ecstatic audience. Overnight, the opera became the only topic of conversation in cultural circles. It was revived the next season, and ran for a record sixty-seven additional performances. Verdi was established as a major new force in Italian theatre.

And the rest, as they say, is history.