Portrait of Antonio Vivaldi (1678-1741) hanging in the Civico Museo Bibliografico Musicale, Bologna. Photograph: Stefano Bianchetti/Corbis
In a development described by music experts as "a bombshell in the world of Baroque opera", a new version of Vivaldi's opera Orlando Furioso has been discovered, 270 years after his death.
The manuscript has been dated to 1714, 13 years before Vivaldi composed his later masterpiece. It contains as many as 20 new arias, never heard before – all composed around the time that Vivaldi was also working on The Four Seasons, said to be the most-recorded piece of classical music in history.
"It's a gift from heaven," said Susan Orlando, a Vivaldi expert. Federico Maria Sardelli, the Vivaldi scholar who initially identified the master's hand, said: "The music is completely new for everybody. It's very exciting." Although the manuscript was among vast numbers of Vivaldi papers in an Italian library, it had been overlooked because it did not bear a composer's name.
In 1714, an Orlando opera was a huge hit at the Teatro San Angelo in Venice, running for 40 performances – a long run at the time. The theatre's directors were Vivaldi and his musician father, but the fact that this opera was by Vivaldi himself went unnoticed by posterity.