Gioachino Rossini was one of the most influential, as well as one of the most industrious and emotionally complex of the great nineteenth-century composers. Between 1810 and 1829, he wrote 39 operas, a body of work, comic and serious, which transformed Italian opera and radically altered the course of opera in France. His retirement from operatic composition in 1829, at the age of 37, was widely assumed to be the act of a talented but lazy man.

In reality, political events and a series of de...