Verdi and Richard Wagner were the greatest composers of opera in the 19th century although they were completely different from one another. When Verdi was a young man the most famous opera composers in Italy were Gaetano Donizetti and Vincenzo Bellini who wrote in the bel canto tradition. This meant that their operas had beautiful tunes which were written for singers to show off their voices, even if what they sang did not suit the story. During his long life Verdi changed opera so that it did not have to obey old-fashioned rules.