Rossini's Masterpiece, "Il barbiere di Siviglia"

In Rossini's day, it was considered a matter of pride just how fast one could turn out a masterpiece. It is said that Rossini wrote Il barbiere di Siviglia
in 20 days. Rossini claimed 11 days.
Years later when Donizetti was asked, he replied, "I believe he wrote it in 20 days. We all know how lazy he was!"