Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

May 7, 1840, was the birthday of one of the most famous Russian composers of the nineteenth century Peter Illich Tchaikovsky. The son of a mining inspector, Tchaikovsky studied music as a child and later studied composition at the St. Petersburg Conservatory. His greatest period of productivity occurred between 1876 and 1890, during which time he enjoyed the patronage of Madame von Meck, a woman he never met, who gave him a living stipend of about $1, 000.00 a year. Madame von Meck later terminated her friendship with Tchaikovsky, as well as his living allowance, when she, herself, was facing financial difficulties. It was during the time of Madame von Meck's patronage, however, that Tchaikovsky created the music for which he is most famous, including the music for the ballets of Swan Lake and The Sleeping Beauty.

Tchaikovsky's music, well known for its rich melodic and sometimes melancholy passages, was one of the first that brought serious dramatic music to dance. Before this, little attention had been given to the music behind the dance. Tchaikovsky died on November 6, 1893, ostensibly of cholera, though there are now some scholars who argue that he committed suicide.

According to the passage, for what is Tchaikovsky's music most well known?