"Nessun dorma" (Italian: [nesˈsun ˈdɔrma]; English: "None shall sleep") is an aria from the final act of Giacomo Puccini's frequently performed opera Turandot and is one of the best-known tenor arias in all opera. It is sung by Calaf, il principe ignoto (the unknown prince), who falls in love at first sight with the beautiful but cold Princess Turandot. However, any man who wishes to wed Turandot must first answer her three riddles; if he fails, he will be beheaded. In the aria, Calaf expresses his triumphant assurance that he will win the princess.

Although "Nessun dorma" has long been a staple of operatic recitals, Luciano Pavarotti popularized the piece beyond the opera world in the 1990s following his performance of it for the 1990 World Cup. Both Pavarotti and Plácido Domingo released singles of the aria that charted in the United Kingdom, and it appeared on the best selling classical album of all time, The Three Tenors in Concert. Since that time, many crossover artists have performed and recorded it. The aria has been sung often in movies and on television.

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