After having solved the three riddles of erotófoba Princess Turandot, with the risk of decapitation at the first attempt failed, the suitor Calaf proposes a riddle turn his newly acquired girlfriend, she should know how to call his unknown lover before daybreak, and if you find the name, he gladly submitted to the executioner risky head. But the princess, complete with royal blood, is half a trick, so he sends his guards and palace spies who torture all over Beijing for the stranger's name is revealed 
. So, by royal edict, no one can sleep that night, on pain of death. This is when Calaf sings his famous aria "Nessun dorma", which no one sleeps, one of the most popular, beloved and accomplished operatic annals. What follows is taken from the Wikipedia:
"Turandot's name has Persian origin and means" daughter of Turan. " Turan was a region of Central Asia, part of the Persian Empire. Turandot history goes back a poem by Nezami, one of the great epic poets of Persian literature, called The seven beauties or The seven princesses. In this poem tells the story of a Persian prince of the Sassanid era, having seven princesses, each from a different part of the empire: Egypt, China, Russia, Greece, Turkey, India and central Asia. Russian princess could not find a man worthy of her, so he had locked himself in a fortress and had declared he would surrender to solve a series of riddles. In addition, once solved the mysteries, had to go through their 'secret door, guarded by mysterious sword that threatens to behead fearless. "
"This story was picked up by François de la Croix, a contemporary French Orientalist Antoine Galland, translator of The Arabian Nights, a collection of stories called The Thousand and One Days . This book makes a cultural transposition of the original Russian princess a cold and cruel princess named Turandokht China, transpose it intended to emphasize the exotic character of the story.
"From this account, a tragicomedy Carlo Gozzi created the comedy style of art that
was then recreated by the German poet Friedrich Schiller. The text the opera is based on an Italian translation of this work. "Puccini began working on Turandot in March 1920, after meeting with librettists Giuseppe Adami and Renato Simoni. Composition began in January 1921. In March 1924, had completed the opera to the final duet. However, had not been satisfied with the script of the duo and did not resume work until October 8, picking the fourth version of the text made Adami. On October 10 he was diagnosed with throat cancer and Puccini died a few weeks later, on November 29, leaving only thirty-six pages with sketches about the end of Turandot . Puccini also left instructions that Riccardo Zandonai finish the opera, but his son Tonio objected to this decision and Franco Alfano was commissioned to complete the work.
"The premiere of Turandot was performed at La Scala in Milan on April 25, 1926, under the musical direction of Arturo Toscanini. "Halfway through the third act, two bars after the words" Liu, poetry! ", Stopped the orchestra, Toscanini dropped his baton, turned to the audience and said 'qui il maestro Fini" ("Here ended the teacher "). The curtain slowly descended. Subsequent representations included the composite end by Alfano.
"In 2002, Luciano Berio composed a new ending for Turandot , which received mixed reviews."
